pub struct NaiveTime { /* private fields */ }
Expand description

ISO 8601 time without timezone. Allows for the nanosecond precision and optional leap second representation.

Leap Second Handling

Since 1960s, the manmade atomic clock has been so accurate that it is much more accurate than Earth’s own motion. It became desirable to define the civil time in terms of the atomic clock, but that risks the desynchronization of the civil time from Earth. To account for this, the designers of the Coordinated Universal Time (UTC) made that the UTC should be kept within 0.9 seconds of the observed Earth-bound time. When the mean solar day is longer than the ideal (86,400 seconds), the error slowly accumulates and it is necessary to add a leap second to slow the UTC down a bit. (We may also remove a second to speed the UTC up a bit, but it never happened.) The leap second, if any, follows 23:59:59 of June 30 or December 31 in the UTC.

Fast forward to the 21st century, we have seen 26 leap seconds from January 1972 to December 2015. Yes, 26 seconds. Probably you can read this paragraph within 26 seconds. But those 26 seconds, and possibly more in the future, are never predictable, and whether to add a leap second or not is known only before 6 months. Internet-based clocks (via NTP) do account for known leap seconds, but the system API normally doesn’t (and often can’t, with no network connection) and there is no reliable way to retrieve leap second information.

Chrono does not try to accurately implement leap seconds; it is impossible. Rather, it allows for leap seconds but behaves as if there are no other leap seconds. Various operations will ignore any possible leap second(s) except when any of the operands were actually leap seconds.

If you cannot tolerate this behavior, you must use a separate TimeZone for the International Atomic Time (TAI). TAI is like UTC but has no leap seconds, and thus slightly differs from UTC. Chrono does not yet provide such implementation, but it is planned.

Representing Leap Seconds

The leap second is indicated via fractional seconds more than 1 second. This makes possible to treat a leap second as the prior non-leap second if you don’t care about sub-second accuracy. You should use the proper formatting to get the raw leap second.

All methods accepting fractional seconds will accept such values.

use chrono::{NaiveDate, NaiveTime, Utc, TimeZone};

let t = NaiveTime::from_hms_milli_opt(8, 59, 59, 1_000).unwrap();

let dt1 = NaiveDate::from_ymd_opt(2015, 7, 1).unwrap().and_hms_micro_opt(8, 59, 59, 1_000_000).unwrap();

let dt2 = NaiveDate::from_ymd_opt(2015, 6, 30).unwrap().and_hms_nano_opt(23, 59, 59, 1_000_000_000).unwrap().and_local_timezone(Utc).unwrap();

Note that the leap second can happen anytime given an appropriate time zone; 2015-07-01 01:23:60 would be a proper leap second if UTC+01:24 had existed. Practically speaking, though, by the time of the first leap second on 1972-06-30, every time zone offset around the world has standardized to the 5-minute alignment.

Date And Time Arithmetics

As a concrete example, let’s assume that 03:00:60 and 04:00:60 are leap seconds. In reality, of course, leap seconds are separated by at least 6 months. We will also use some intuitive concise notations for the explanation.

Time + Duration (short for NaiveTime::overflowing_add_signed):

  • 03:00:00 + 1s = 03:00:01.
  • 03:00:59 + 60s = 03:02:00.
  • 03:00:59 + 1s = 03:01:00.
  • 03:00:60 + 1s = 03:01:00. Note that the sum is identical to the previous.
  • 03:00:60 + 60s = 03:01:59.
  • 03:00:60 + 61s = 03:02:00.
  • 03:00:60.1 + 0.8s = 03:00:60.9.

Time - Duration (short for NaiveTime::overflowing_sub_signed):

  • 03:00:00 - 1s = 02:59:59.
  • 03:01:00 - 1s = 03:00:59.
  • 03:01:00 - 60s = 03:00:00.
  • 03:00:60 - 60s = 03:00:00. Note that the result is identical to the previous.
  • 03:00:60.7 - 0.4s = 03:00:60.3.
  • 03:00:60.7 - 0.9s = 03:00:59.8.

Time - Time (short for NaiveTime::signed_duration_since):

  • 04:00:00 - 03:00:00 = 3600s.
  • 03:01:00 - 03:00:00 = 60s.
  • 03:00:60 - 03:00:00 = 60s. Note that the difference is identical to the previous.
  • 03:00:60.6 - 03:00:59.4 = 1.2s.
  • 03:01:00 - 03:00:59.8 = 0.2s.
  • 03:01:00 - 03:00:60.5 = 0.5s. Note that the difference is larger than the previous, even though the leap second clearly follows the previous whole second.
  • 04:00:60.9 - 03:00:60.1 = (04:00:60.9 - 04:00:00) + (04:00:00 - 03:01:00) + (03:01:00 - 03:00:60.1) = 60.9s + 3540s + 0.9s = 3601.8s.

In general,

  • Time + Duration unconditionally equals to Duration + Time.

  • Time - Duration unconditionally equals to Time + (-Duration).

  • Time1 - Time2 unconditionally equals to -(Time2 - Time1).

  • Associativity does not generally hold, because (Time + Duration1) - Duration2 no longer equals to Time + (Duration1 - Duration2) for two positive durations.

    • As a special case, (Time + Duration) - Duration also does not equal to Time.

    • If you can assume that all durations have the same sign, however, then the associativity holds: (Time + Duration1) + Duration2 equals to Time + (Duration1 + Duration2) for two positive durations.

Reading And Writing Leap Seconds

The “typical” leap seconds on the minute boundary are correctly handled both in the formatting and parsing. The leap second in the human-readable representation will be represented as the second part being 60, as required by ISO 8601.

use chrono::{Utc, TimeZone, NaiveDate};

let dt = NaiveDate::from_ymd_opt(2015, 6, 30).unwrap().and_hms_milli_opt(23, 59, 59, 1_000).unwrap().and_local_timezone(Utc).unwrap();
assert_eq!(format!("{:?}", dt), "2015-06-30T23:59:60Z");

There are hypothetical leap seconds not on the minute boundary nevertheless supported by Chrono. They are allowed for the sake of completeness and consistency; there were several “exotic” time zone offsets with fractional minutes prior to UTC after all. For such cases the human-readable representation is ambiguous and would be read back to the next non-leap second.

use chrono::{DateTime, Utc, TimeZone, NaiveDate};

let dt = NaiveDate::from_ymd_opt(2015, 6, 30).unwrap().and_hms_milli_opt(23, 56, 4, 1_000).unwrap().and_local_timezone(Utc).unwrap();
assert_eq!(format!("{:?}", dt), "2015-06-30T23:56:05Z");

let dt = Utc.with_ymd_and_hms(2015, 6, 30, 23, 56, 5).unwrap();
assert_eq!(format!("{:?}", dt), "2015-06-30T23:56:05Z");
assert_eq!(DateTime::parse_from_rfc3339("2015-06-30T23:56:05Z").unwrap(), dt);

Since Chrono alone cannot determine any existence of leap seconds, there is absolutely no guarantee that the leap second read has actually happened.

Implementations

👎Deprecated since 0.4.23: use from_hms_opt() instead

Makes a new NaiveTime from hour, minute and second.

No leap second is allowed here; use NaiveTime::from_hms_* methods with a subsecond parameter instead.

Panics on invalid hour, minute and/or second.

Makes a new NaiveTime from hour, minute and second.

No leap second is allowed here; use NaiveTime::from_hms_*_opt methods with a subsecond parameter instead.

Returns None on invalid hour, minute and/or second.

Example
use chrono::NaiveTime;

let from_hms_opt = NaiveTime::from_hms_opt;

assert!(from_hms_opt(0, 0, 0).is_some());
assert!(from_hms_opt(23, 59, 59).is_some());
assert!(from_hms_opt(24, 0, 0).is_none());
assert!(from_hms_opt(23, 60, 0).is_none());
assert!(from_hms_opt(23, 59, 60).is_none());
👎Deprecated since 0.4.23: use from_hms_milli_opt() instead

Makes a new NaiveTime from hour, minute, second and millisecond.

The millisecond part can exceed 1,000 in order to represent the leap second.

Panics on invalid hour, minute, second and/or millisecond.

Makes a new NaiveTime from hour, minute, second and millisecond.

The millisecond part can exceed 1,000 in order to represent the leap second.

Returns None on invalid hour, minute, second and/or millisecond.

Example
use chrono::NaiveTime;

let from_hmsm_opt = NaiveTime::from_hms_milli_opt;

assert!(from_hmsm_opt(0, 0, 0, 0).is_some());
assert!(from_hmsm_opt(23, 59, 59, 999).is_some());
assert!(from_hmsm_opt(23, 59, 59, 1_999).is_some()); // a leap second after 23:59:59
assert!(from_hmsm_opt(24, 0, 0, 0).is_none());
assert!(from_hmsm_opt(23, 60, 0, 0).is_none());
assert!(from_hmsm_opt(23, 59, 60, 0).is_none());
assert!(from_hmsm_opt(23, 59, 59, 2_000).is_none());
👎Deprecated since 0.4.23: use from_hms_micro_opt() instead

Makes a new NaiveTime from hour, minute, second and microsecond.

The microsecond part can exceed 1,000,000 in order to represent the leap second.

Panics on invalid hour, minute, second and/or microsecond.

Makes a new NaiveTime from hour, minute, second and microsecond.

The microsecond part can exceed 1,000,000 in order to represent the leap second.

Returns None on invalid hour, minute, second and/or microsecond.

Example
use chrono::NaiveTime;

let from_hmsu_opt = NaiveTime::from_hms_micro_opt;

assert!(from_hmsu_opt(0, 0, 0, 0).is_some());
assert!(from_hmsu_opt(23, 59, 59, 999_999).is_some());
assert!(from_hmsu_opt(23, 59, 59, 1_999_999).is_some()); // a leap second after 23:59:59
assert!(from_hmsu_opt(24, 0, 0, 0).is_none());
assert!(from_hmsu_opt(23, 60, 0, 0).is_none());
assert!(from_hmsu_opt(23, 59, 60, 0).is_none());
assert!(from_hmsu_opt(23, 59, 59, 2_000_000).is_none());
👎Deprecated since 0.4.23: use from_hms_nano_opt() instead

Makes a new NaiveTime from hour, minute, second and nanosecond.

The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.

Panics on invalid hour, minute, second and/or nanosecond.

Makes a new NaiveTime from hour, minute, second and nanosecond.

The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.

Returns None on invalid hour, minute, second and/or nanosecond.

Example
use chrono::NaiveTime;

let from_hmsn_opt = NaiveTime::from_hms_nano_opt;

assert!(from_hmsn_opt(0, 0, 0, 0).is_some());
assert!(from_hmsn_opt(23, 59, 59, 999_999_999).is_some());
assert!(from_hmsn_opt(23, 59, 59, 1_999_999_999).is_some()); // a leap second after 23:59:59
assert!(from_hmsn_opt(24, 0, 0, 0).is_none());
assert!(from_hmsn_opt(23, 60, 0, 0).is_none());
assert!(from_hmsn_opt(23, 59, 60, 0).is_none());
assert!(from_hmsn_opt(23, 59, 59, 2_000_000_000).is_none());
👎Deprecated since 0.4.23: use from_num_seconds_from_midnight_opt() instead

Makes a new NaiveTime from the number of seconds since midnight and nanosecond.

The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.

Panics on invalid number of seconds and/or nanosecond.

Makes a new NaiveTime from the number of seconds since midnight and nanosecond.

The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.

Returns None on invalid number of seconds and/or nanosecond.

Example
use chrono::NaiveTime;

let from_nsecs_opt = NaiveTime::from_num_seconds_from_midnight_opt;

assert!(from_nsecs_opt(0, 0).is_some());
assert!(from_nsecs_opt(86399, 999_999_999).is_some());
assert!(from_nsecs_opt(86399, 1_999_999_999).is_some()); // a leap second after 23:59:59
assert!(from_nsecs_opt(86_400, 0).is_none());
assert!(from_nsecs_opt(86399, 2_000_000_000).is_none());

Parses a string with the specified format string and returns a new NaiveTime. See the format::strftime module on the supported escape sequences.

Example
use chrono::NaiveTime;

let parse_from_str = NaiveTime::parse_from_str;

assert_eq!(parse_from_str("23:56:04", "%H:%M:%S"),
           Ok(NaiveTime::from_hms_opt(23, 56, 4).unwrap()));
assert_eq!(parse_from_str("pm012345.6789", "%p%I%M%S%.f"),
           Ok(NaiveTime::from_hms_micro_opt(13, 23, 45, 678_900).unwrap()));

Date and offset is ignored for the purpose of parsing.

assert_eq!(parse_from_str("2014-5-17T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z"),
           Ok(NaiveTime::from_hms_opt(12, 34, 56).unwrap()));

Leap seconds are correctly handled by treating any time of the form hh:mm:60 as a leap second. (This equally applies to the formatting, so the round trip is possible.)

assert_eq!(parse_from_str("08:59:60.123", "%H:%M:%S%.f"),
           Ok(NaiveTime::from_hms_milli_opt(8, 59, 59, 1_123).unwrap()));

Missing seconds are assumed to be zero, but out-of-bound times or insufficient fields are errors otherwise.

assert_eq!(parse_from_str("7:15", "%H:%M"),
           Ok(NaiveTime::from_hms_opt(7, 15, 0).unwrap()));

assert!(parse_from_str("04m33s", "%Mm%Ss").is_err());
assert!(parse_from_str("12", "%H").is_err());
assert!(parse_from_str("17:60", "%H:%M").is_err());
assert!(parse_from_str("24:00:00", "%H:%M:%S").is_err());

All parsed fields should be consistent to each other, otherwise it’s an error. Here %H is for 24-hour clocks, unlike %I, and thus can be independently determined without AM/PM.

assert!(parse_from_str("13:07 AM", "%H:%M %p").is_err());

Adds given Duration to the current time, and also returns the number of seconds in the integral number of days ignored from the addition. (We cannot return Duration because it is subject to overflow or underflow.)

Example
use chrono::{Duration, NaiveTime};

let from_hms = NaiveTime::from_hms;

assert_eq!(from_hms(3, 4, 5).overflowing_add_signed(Duration::hours(11)),
           (from_hms(14, 4, 5), 0));
assert_eq!(from_hms(3, 4, 5).overflowing_add_signed(Duration::hours(23)),
           (from_hms(2, 4, 5), 86_400));
assert_eq!(from_hms(3, 4, 5).overflowing_add_signed(Duration::hours(-7)),
           (from_hms(20, 4, 5), -86_400));

Subtracts given Duration from the current time, and also returns the number of seconds in the integral number of days ignored from the subtraction. (We cannot return Duration because it is subject to overflow or underflow.)

Example
use chrono::{Duration, NaiveTime};

let from_hms = NaiveTime::from_hms;

assert_eq!(from_hms(3, 4, 5).overflowing_sub_signed(Duration::hours(2)),
           (from_hms(1, 4, 5), 0));
assert_eq!(from_hms(3, 4, 5).overflowing_sub_signed(Duration::hours(17)),
           (from_hms(10, 4, 5), 86_400));
assert_eq!(from_hms(3, 4, 5).overflowing_sub_signed(Duration::hours(-22)),
           (from_hms(1, 4, 5), -86_400));

Subtracts another NaiveTime from the current time. Returns a Duration within +/- 1 day. This does not overflow or underflow at all.

As a part of Chrono’s leap second handling, the subtraction assumes that there is no leap second ever, except when any of the NaiveTimes themselves represents a leap second in which case the assumption becomes that there are exactly one (or two) leap second(s) ever.

Example
use chrono::{Duration, NaiveTime};

let from_hmsm = NaiveTime::from_hms_milli;
let since = NaiveTime::signed_duration_since;

assert_eq!(since(from_hmsm(3, 5, 7, 900), from_hmsm(3, 5, 7, 900)),
           Duration::zero());
assert_eq!(since(from_hmsm(3, 5, 7, 900), from_hmsm(3, 5, 7, 875)),
           Duration::milliseconds(25));
assert_eq!(since(from_hmsm(3, 5, 7, 900), from_hmsm(3, 5, 6, 925)),
           Duration::milliseconds(975));
assert_eq!(since(from_hmsm(3, 5, 7, 900), from_hmsm(3, 5, 0, 900)),
           Duration::seconds(7));
assert_eq!(since(from_hmsm(3, 5, 7, 900), from_hmsm(3, 0, 7, 900)),
           Duration::seconds(5 * 60));
assert_eq!(since(from_hmsm(3, 5, 7, 900), from_hmsm(0, 5, 7, 900)),
           Duration::seconds(3 * 3600));
assert_eq!(since(from_hmsm(3, 5, 7, 900), from_hmsm(4, 5, 7, 900)),
           Duration::seconds(-3600));
assert_eq!(since(from_hmsm(3, 5, 7, 900), from_hmsm(2, 4, 6, 800)),
           Duration::seconds(3600 + 60 + 1) + Duration::milliseconds(100));

Leap seconds are handled, but the subtraction assumes that there were no other leap seconds happened.

assert_eq!(since(from_hmsm(3, 0, 59, 1_000), from_hmsm(3, 0, 59, 0)),
           Duration::seconds(1));
assert_eq!(since(from_hmsm(3, 0, 59, 1_500), from_hmsm(3, 0, 59, 0)),
           Duration::milliseconds(1500));
assert_eq!(since(from_hmsm(3, 0, 59, 1_000), from_hmsm(3, 0, 0, 0)),
           Duration::seconds(60));
assert_eq!(since(from_hmsm(3, 0, 0, 0), from_hmsm(2, 59, 59, 1_000)),
           Duration::seconds(1));
assert_eq!(since(from_hmsm(3, 0, 59, 1_000), from_hmsm(2, 59, 59, 1_000)),
           Duration::seconds(61));

Formats the time with the specified formatting items. Otherwise it is the same as the ordinary format method.

The Iterator of items should be Cloneable, since the resulting DelayedFormat value may be formatted multiple times.

Example
use chrono::NaiveTime;
use chrono::format::strftime::StrftimeItems;

let fmt = StrftimeItems::new("%H:%M:%S");
let t = NaiveTime::from_hms_opt(23, 56, 4).unwrap();
assert_eq!(t.format_with_items(fmt.clone()).to_string(), "23:56:04");
assert_eq!(t.format("%H:%M:%S").to_string(),             "23:56:04");

The resulting DelayedFormat can be formatted directly via the Display trait.

assert_eq!(format!("{}", t.format_with_items(fmt)), "23:56:04");

Formats the time with the specified format string. See the format::strftime module on the supported escape sequences.

This returns a DelayedFormat, which gets converted to a string only when actual formatting happens. You may use the to_string method to get a String, or just feed it into print! and other formatting macros. (In this way it avoids the redundant memory allocation.)

A wrong format string does not issue an error immediately. Rather, converting or formatting the DelayedFormat fails. You are recommended to immediately use DelayedFormat for this reason.

Example
use chrono::NaiveTime;

let t = NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap();
assert_eq!(t.format("%H:%M:%S").to_string(), "23:56:04");
assert_eq!(t.format("%H:%M:%S%.6f").to_string(), "23:56:04.012345");
assert_eq!(t.format("%-I:%M %p").to_string(), "11:56 PM");

The resulting DelayedFormat can be formatted directly via the Display trait.

assert_eq!(format!("{}", t.format("%H:%M:%S")), "23:56:04");
assert_eq!(format!("{}", t.format("%H:%M:%S%.6f")), "23:56:04.012345");
assert_eq!(format!("{}", t.format("%-I:%M %p")), "11:56 PM");

Trait Implementations

An addition of Duration to NaiveTime wraps around and never overflows or underflows. In particular the addition ignores integral number of days.

As a part of Chrono’s leap second handling, the addition assumes that there is no leap second ever, except when the NaiveTime itself represents a leap second in which case the assumption becomes that there is exactly a single leap second ever.

Example

use chrono::{Duration, NaiveTime};

let from_hmsm = NaiveTime::from_hms_milli;

assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::zero(),                  from_hmsm(3, 5, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::seconds(1),              from_hmsm(3, 5, 8, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::seconds(-1),             from_hmsm(3, 5, 6, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::seconds(60 + 4),         from_hmsm(3, 6, 11, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::seconds(7*60*60 - 6*60), from_hmsm(9, 59, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::milliseconds(80),        from_hmsm(3, 5, 7, 80));
assert_eq!(from_hmsm(3, 5, 7, 950) + Duration::milliseconds(280),     from_hmsm(3, 5, 8, 230));
assert_eq!(from_hmsm(3, 5, 7, 950) + Duration::milliseconds(-980),    from_hmsm(3, 5, 6, 970));

The addition wraps around.

assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::seconds(22*60*60), from_hmsm(1, 5, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::seconds(-8*60*60), from_hmsm(19, 5, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) + Duration::days(800),         from_hmsm(3, 5, 7, 0));

Leap seconds are handled, but the addition assumes that it is the only leap second happened.

let leap = from_hmsm(3, 5, 59, 1_300);
assert_eq!(leap + Duration::zero(),             from_hmsm(3, 5, 59, 1_300));
assert_eq!(leap + Duration::milliseconds(-500), from_hmsm(3, 5, 59, 800));
assert_eq!(leap + Duration::milliseconds(500),  from_hmsm(3, 5, 59, 1_800));
assert_eq!(leap + Duration::milliseconds(800),  from_hmsm(3, 6, 0, 100));
assert_eq!(leap + Duration::seconds(10),        from_hmsm(3, 6, 9, 300));
assert_eq!(leap + Duration::seconds(-10),       from_hmsm(3, 5, 50, 300));
assert_eq!(leap + Duration::days(1),            from_hmsm(3, 5, 59, 300));
The resulting type after applying the + operator.
Performs the + operation. Read more
The resulting type after applying the + operator.
Performs the + operation. Read more
Performs the += operation. Read more
Returns a copy of the value. Read more
Performs copy-assignment from source. Read more

The Debug output of the naive time t is the same as t.format("%H:%M:%S%.f").

The string printed can be readily parsed via the parse method on str.

It should be noted that, for leap seconds not on the minute boundary, it may print a representation not distinguishable from non-leap seconds. This doesn’t matter in practice, since such leap seconds never happened. (By the time of the first leap second on 1972-06-30, every time zone offset around the world has standardized to the 5-minute alignment.)

Example

use chrono::NaiveTime;

assert_eq!(format!("{:?}", NaiveTime::from_hms_opt(23, 56, 4).unwrap()),              "23:56:04");
assert_eq!(format!("{:?}", NaiveTime::from_hms_milli_opt(23, 56, 4, 12).unwrap()),    "23:56:04.012");
assert_eq!(format!("{:?}", NaiveTime::from_hms_micro_opt(23, 56, 4, 1234).unwrap()),  "23:56:04.001234");
assert_eq!(format!("{:?}", NaiveTime::from_hms_nano_opt(23, 56, 4, 123456).unwrap()), "23:56:04.000123456");

Leap seconds may also be used.

assert_eq!(format!("{:?}", NaiveTime::from_hms_milli_opt(6, 59, 59, 1_500).unwrap()), "06:59:60.500");
Formats the value using the given formatter. Read more

The default value for a NaiveTime is midnight, 00:00:00 exactly.

Example

use chrono::NaiveTime;

let default_time = NaiveTime::default();
assert_eq!(default_time, NaiveTime::from_hms_opt(0, 0, 0).unwrap());
Returns the “default value” for a type. Read more
Deserialize this value from the given Serde deserializer. Read more

The Display output of the naive time t is the same as t.format("%H:%M:%S%.f").

The string printed can be readily parsed via the parse method on str.

It should be noted that, for leap seconds not on the minute boundary, it may print a representation not distinguishable from non-leap seconds. This doesn’t matter in practice, since such leap seconds never happened. (By the time of the first leap second on 1972-06-30, every time zone offset around the world has standardized to the 5-minute alignment.)

Example

use chrono::NaiveTime;

assert_eq!(format!("{}", NaiveTime::from_hms_opt(23, 56, 4).unwrap()),              "23:56:04");
assert_eq!(format!("{}", NaiveTime::from_hms_milli_opt(23, 56, 4, 12).unwrap()),    "23:56:04.012");
assert_eq!(format!("{}", NaiveTime::from_hms_micro_opt(23, 56, 4, 1234).unwrap()),  "23:56:04.001234");
assert_eq!(format!("{}", NaiveTime::from_hms_nano_opt(23, 56, 4, 123456).unwrap()), "23:56:04.000123456");

Leap seconds may also be used.

assert_eq!(format!("{}", NaiveTime::from_hms_milli_opt(6, 59, 59, 1_500).unwrap()), "06:59:60.500");
Formats the value using the given formatter. Read more

Parsing a str into a NaiveTime uses the same format, %H:%M:%S%.f, as in Debug and Display.

Example

use chrono::NaiveTime;

let t = NaiveTime::from_hms_opt(23, 56, 4).unwrap();
assert_eq!("23:56:04".parse::<NaiveTime>(), Ok(t));

let t = NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap();
assert_eq!("23:56:4.012345678".parse::<NaiveTime>(), Ok(t));

let t = NaiveTime::from_hms_nano_opt(23, 59, 59, 1_234_567_890).unwrap(); // leap second
assert_eq!("23:59:60.23456789".parse::<NaiveTime>(), Ok(t));

assert!("foo".parse::<NaiveTime>().is_err());
The associated error which can be returned from parsing.
Parses a string s to return a value of this type. Read more
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
This method returns an Ordering between self and other. Read more
Compares and returns the maximum of two values. Read more
Compares and returns the minimum of two values. Read more
Restrict a value to a certain interval. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
Serialize this value into the given Serde serializer. Read more

A subtraction of Duration from NaiveTime wraps around and never overflows or underflows. In particular the addition ignores integral number of days. It is the same as the addition with a negated Duration.

As a part of Chrono’s leap second handling, the addition assumes that there is no leap second ever, except when the NaiveTime itself represents a leap second in which case the assumption becomes that there is exactly a single leap second ever.

Example

use chrono::{Duration, NaiveTime};

let from_hmsm = NaiveTime::from_hms_milli;

assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::zero(),                  from_hmsm(3, 5, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::seconds(1),              from_hmsm(3, 5, 6, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::seconds(60 + 5),         from_hmsm(3, 4, 2, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::seconds(2*60*60 + 6*60), from_hmsm(0, 59, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::milliseconds(80),        from_hmsm(3, 5, 6, 920));
assert_eq!(from_hmsm(3, 5, 7, 950) - Duration::milliseconds(280),     from_hmsm(3, 5, 7, 670));

The subtraction wraps around.

assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::seconds(8*60*60), from_hmsm(19, 5, 7, 0));
assert_eq!(from_hmsm(3, 5, 7, 0) - Duration::days(800),        from_hmsm(3, 5, 7, 0));

Leap seconds are handled, but the subtraction assumes that it is the only leap second happened.

let leap = from_hmsm(3, 5, 59, 1_300);
assert_eq!(leap - Duration::zero(),            from_hmsm(3, 5, 59, 1_300));
assert_eq!(leap - Duration::milliseconds(200), from_hmsm(3, 5, 59, 1_100));
assert_eq!(leap - Duration::milliseconds(500), from_hmsm(3, 5, 59, 800));
assert_eq!(leap - Duration::seconds(60),       from_hmsm(3, 5, 0, 300));
assert_eq!(leap - Duration::days(1),           from_hmsm(3, 6, 0, 300));
The resulting type after applying the - operator.
Performs the - operation. Read more
The resulting type after applying the - operator.
Performs the - operation. Read more

Subtracts another NaiveTime from the current time. Returns a Duration within +/- 1 day. This does not overflow or underflow at all.

As a part of Chrono’s leap second handling, the subtraction assumes that there is no leap second ever, except when any of the NaiveTimes themselves represents a leap second in which case the assumption becomes that there are exactly one (or two) leap second(s) ever.

The implementation is a wrapper around NaiveTime::signed_duration_since.

Example

use chrono::{Duration, NaiveTime};

let from_hmsm = NaiveTime::from_hms_milli;

assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 5, 7, 900), Duration::zero());
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 5, 7, 875), Duration::milliseconds(25));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 5, 6, 925), Duration::milliseconds(975));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 5, 0, 900), Duration::seconds(7));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(3, 0, 7, 900), Duration::seconds(5 * 60));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(0, 5, 7, 900), Duration::seconds(3 * 3600));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(4, 5, 7, 900), Duration::seconds(-3600));
assert_eq!(from_hmsm(3, 5, 7, 900) - from_hmsm(2, 4, 6, 800),
           Duration::seconds(3600 + 60 + 1) + Duration::milliseconds(100));

Leap seconds are handled, but the subtraction assumes that there were no other leap seconds happened.

assert_eq!(from_hmsm(3, 0, 59, 1_000) - from_hmsm(3, 0, 59, 0), Duration::seconds(1));
assert_eq!(from_hmsm(3, 0, 59, 1_500) - from_hmsm(3, 0, 59, 0),
           Duration::milliseconds(1500));
assert_eq!(from_hmsm(3, 0, 59, 1_000) - from_hmsm(3, 0, 0, 0), Duration::seconds(60));
assert_eq!(from_hmsm(3, 0, 0, 0) - from_hmsm(2, 59, 59, 1_000), Duration::seconds(1));
assert_eq!(from_hmsm(3, 0, 59, 1_000) - from_hmsm(2, 59, 59, 1_000),
           Duration::seconds(61));
The resulting type after applying the - operator.
Performs the - operation. Read more
Performs the -= operation. Read more

Returns the hour number from 0 to 23.

Example
use chrono::{NaiveTime, Timelike};

assert_eq!(NaiveTime::from_hms_opt(0, 0, 0).unwrap().hour(), 0);
assert_eq!(NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap().hour(), 23);

Returns the minute number from 0 to 59.

Example
use chrono::{NaiveTime, Timelike};

assert_eq!(NaiveTime::from_hms_opt(0, 0, 0).unwrap().minute(), 0);
assert_eq!(NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap().minute(), 56);

Returns the second number from 0 to 59.

Example
use chrono::{NaiveTime, Timelike};

assert_eq!(NaiveTime::from_hms_opt(0, 0, 0).unwrap().second(), 0);
assert_eq!(NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap().second(), 4);

This method never returns 60 even when it is a leap second. (Why?) Use the proper formatting method to get a human-readable representation.

let leap = NaiveTime::from_hms_milli_opt(23, 59, 59, 1_000).unwrap();
assert_eq!(leap.second(), 59);
assert_eq!(leap.format("%H:%M:%S").to_string(), "23:59:60");

Returns the number of nanoseconds since the whole non-leap second. The range from 1,000,000,000 to 1,999,999,999 represents the leap second.

Example
use chrono::{NaiveTime, Timelike};

assert_eq!(NaiveTime::from_hms_opt(0, 0, 0).unwrap().nanosecond(), 0);
assert_eq!(NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap().nanosecond(), 12_345_678);

Leap seconds may have seemingly out-of-range return values. You can reduce the range with time.nanosecond() % 1_000_000_000, or use the proper formatting method to get a human-readable representation.

let leap = NaiveTime::from_hms_milli_opt(23, 59, 59, 1_000).unwrap();
assert_eq!(leap.nanosecond(), 1_000_000_000);
assert_eq!(leap.format("%H:%M:%S%.9f").to_string(), "23:59:60.000000000");

Makes a new NaiveTime with the hour number changed.

Returns None when the resulting NaiveTime would be invalid.

Example
use chrono::{NaiveTime, Timelike};

let dt = NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap();
assert_eq!(dt.with_hour(7), Some(NaiveTime::from_hms_nano_opt(7, 56, 4, 12_345_678).unwrap()));
assert_eq!(dt.with_hour(24), None);

Makes a new NaiveTime with the minute number changed.

Returns None when the resulting NaiveTime would be invalid.

Example
use chrono::{NaiveTime, Timelike};

let dt = NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap();
assert_eq!(dt.with_minute(45), Some(NaiveTime::from_hms_nano_opt(23, 45, 4, 12_345_678).unwrap()));
assert_eq!(dt.with_minute(60), None);

Makes a new NaiveTime with the second number changed.

Returns None when the resulting NaiveTime would be invalid. As with the second method, the input range is restricted to 0 through 59.

Example
use chrono::{NaiveTime, Timelike};

let dt = NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap();
assert_eq!(dt.with_second(17), Some(NaiveTime::from_hms_nano_opt(23, 56, 17, 12_345_678).unwrap()));
assert_eq!(dt.with_second(60), None);

Makes a new NaiveTime with nanoseconds since the whole non-leap second changed.

Returns None when the resulting NaiveTime would be invalid. As with the nanosecond method, the input range can exceed 1,000,000,000 for leap seconds.

Example
use chrono::{NaiveTime, Timelike};

let dt = NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap();
assert_eq!(dt.with_nanosecond(333_333_333),
           Some(NaiveTime::from_hms_nano_opt(23, 56, 4, 333_333_333).unwrap()));
assert_eq!(dt.with_nanosecond(2_000_000_000), None);

Leap seconds can theoretically follow any whole second. The following would be a proper leap second at the time zone offset of UTC-00:03:57 (there are several historical examples comparable to this “non-sense” offset), and therefore is allowed.

assert_eq!(dt.with_nanosecond(1_333_333_333),
           Some(NaiveTime::from_hms_nano_opt(23, 56, 4, 1_333_333_333).unwrap()));

Returns the number of non-leap seconds past the last midnight.

Example
use chrono::{NaiveTime, Timelike};

assert_eq!(NaiveTime::from_hms_opt(1, 2, 3).unwrap().num_seconds_from_midnight(),
           3723);
assert_eq!(NaiveTime::from_hms_nano_opt(23, 56, 4, 12_345_678).unwrap().num_seconds_from_midnight(),
           86164);
assert_eq!(NaiveTime::from_hms_milli_opt(23, 59, 59, 1_000).unwrap().num_seconds_from_midnight(),
           86399);
Returns the hour number from 1 to 12 with a boolean flag, which is false for AM and true for PM. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
Converts the given value to a String. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.