package core_kernel

  1. Overview
  2. Docs
package core_kernel
Legend:
Library
Module
Module type
Parameter
Class
Class type
type underlying = float
type t = private underlying
include sig ... end
val bin_read_t : t Bin_prot.Read.reader
val __bin_read_t__ : (Base.Int.t -> t) Bin_prot.Read.reader
val bin_reader_t : t Bin_prot.Type_class.reader
val bin_size_t : t Bin_prot.Size.sizer
val bin_write_t : t Bin_prot.Write.writer
val bin_writer_t : t Bin_prot.Type_class.writer
val bin_shape_t : Bin_prot.Shape.t
val hash_fold_t : Base.Hash.state -> t -> Base.Hash.state
val hash : t -> Base.Hash.hash_value
val typerep_of_t : t Typerep_lib.Std.Typerep.t
val typename_of_t : t Typerep_lib.Std.Typename.t
module Span : sig ... end
module Ofday : sig ... end
module Replace_polymorphic_compare : sig ... end
include Base.Comparable_intf.Polymorphic_compare with type t := t
include Base.Comparisons.Infix with type t := t
include Interfaces.Robustly_comparable with type t := t
val (>=.) : t -> t -> bool
val (<=.) : t -> t -> bool
val (=.) : t -> t -> bool
val (>.) : t -> t -> bool
val (<.) : t -> t -> bool
val (<>.) : t -> t -> bool
val robustly_compare : t -> t -> int
val next : t -> t

next t returns the next t (forwards in time)

val prev : t -> t

prev t returns the previous t (backwards in time)

val to_span_since_epoch : t -> Span.t
val of_span_since_epoch : Span.t -> t
include Comparable.S_common with type t := t and module Replace_polymorphic_compare := Replace_polymorphic_compare
include Base.Comparable_intf.S with type t := t
include Base.Comparable_intf.Polymorphic_compare with type t := t
include Base.Comparisons.Infix with type t := t
val (>=) : t -> t -> bool
val (<=) : t -> t -> bool
val (=) : t -> t -> bool
val (>) : t -> t -> bool
val (<) : t -> t -> bool
val (<>) : t -> t -> bool
val equal : t -> t -> bool
val compare : t -> t -> int

compare t1 t2 returns 0 if t1 is equal to t2, a negative integer if t1 is less than t2, and a positive integer if t1 is greater than t2.

val min : t -> t -> t
val max : t -> t -> t
val ascending : t -> t -> int

ascending is identical to compare. descending x y = ascending y x. These are intended to be mnemonic when used like List.sort ~cmp:ascending and List.sort ~cmp:descending, since they cause the list to be sorted in ascending or descending order, respectively.

val descending : t -> t -> int
val between : t -> low:t -> high:t -> bool
val clamp_exn : t -> min:t -> max:t -> t

clamp_exn t ~min ~max returns t', the closest value to t such that between t' ~low:min ~high:max is true.

Raises if not (min <= max).

val clamp : t -> min:t -> max:t -> t Base.Or_error.t
include Base.Comparator.S with type t := t
type comparator_witness
include Base.Comparable_intf.Validate with type t := t
val validate_lbound : min:t Base.Maybe_bound.t -> t Base.Validate.check
val validate_ubound : max:t Base.Maybe_bound.t -> t Base.Validate.check
val validate_bound : min:t Base.Maybe_bound.t -> max:t Base.Maybe_bound.t -> t Base.Validate.check
module Relative_to_unspecified_zone : sig ... end

Represents a timezone-relative time, rather than an absolute time. This is equivalent to a Date.t and an Ofday.t with no time zone. A Relative_to_unspecified_zone.t does not correspond to a single, unambiguous point in time. Intended as a low-level back-end for high-level timezone-based functions; most clients should not use Relative_to_unspecified_zone.t.

val now : Base.Unit.t -> t

now () returns a t representing the current time

module Zone : sig ... end
Basic operations on times
val add : t -> Span.t -> t

add t s adds the span s to time t and returns the resulting time.

NOTE: adding spans as a means of adding days is not accurate, and may run into trouble due to shifts in daylight savings time, float arithmetic issues, and leap seconds. See the comment at the top of Zone.mli for a more complete discussion of some of the issues of time-keeping. For spans that cross date boundaries, use date functions instead.

val sub : t -> Span.t -> t

sub t s subtracts the span s from time t and returns the resulting time. See important note for add.

val diff : t -> t -> Span.t

diff t1 t2 returns time t1 minus time t2.

val abs_diff : t -> t -> Span.t

abs_diff t1 t2 returns the absolute span of time t1 minus time t2.

Comparisons
val is_earlier : t -> than:t -> Base.Bool.t
val is_later : t -> than:t -> Base.Bool.t
Conversions
val of_date_ofday : zone:Zone.t -> Core_kernel__.Date0.t -> Ofday.t -> t
val of_date_ofday_precise : Core_kernel__.Date0.t -> Ofday.t -> zone:Zone.t -> [ `Once of t | `Twice of t * t | `Never of t ]

Because timezone offsets change throughout the year (clocks go forward or back) some local times can occur twice or not at all. In the case that they occur twice, this function gives `Twice with both occurrences in order; if they do not occur at all, this function gives `Never with the time at which the local clock skips over the desired time of day.

Note that this is really only intended to work with DST transitions and not unusual or dramatic changes, like the calendar change in 1752 (run "cal 9 1752" in a shell to see). In particular it makes the assumption that midnight of each day is unambiguous.

Most callers should use of_date_ofday rather than this function. In the `Twice and `Never cases, of_date_ofday will return reasonable times for most uses.

val to_date_ofday : t -> zone:Zone.t -> Core_kernel__.Date0.t * Ofday.t
val to_date_ofday_precise : t -> zone:Zone.t -> Core_kernel__.Date0.t * Ofday.t * [ `Only | `Also_at of t | `Also_skipped of Core_kernel__.Date0.t * Ofday.t ]

Always returns the Date.t * Ofday.t that to_date_ofday would have returned, and in addition returns a variant indicating whether the time is associated with a time zone transition.

      - `Only         -> there is a one-to-one mapping between [t]'s and
                         [Date.t * Ofday.t] pairs
      - `Also_at      -> there is another [t] that maps to the same [Date.t * Ofday.t]
                         (this date/time pair happened twice because the clock fell back)
      - `Also_skipped -> there is another [Date.t * Ofday.t] pair that never happened (due
                         to a jump forward) that [of_date_ofday] would map to the same
                         [t].
val to_date : t -> zone:Zone.t -> Core_kernel__.Date0.t
val to_ofday : t -> zone:Zone.t -> Ofday.t
val reset_gmtime_cache : Base.Unit.t -> Base.Unit.t

For performance testing only; reset_gmtime_cache () resets an internal cache used to speed up to_date_ofday and related functions when called repeatedly on times that fall within the same day.

Unlike Time_ns, this module purposely omits max_value and min_value: 1. They produce unintuitive corner cases because most people's mental models of time do not include +/- infinity as concrete values 2. In practice, when people ask for these values, it is for questionable uses, e.g., as null values to use in place of explicit options.

val epoch : t

midnight, Jan 1, 1970 in UTC

val convert : from_tz:Zone.t -> to_tz:Zone.t -> Core_kernel__.Date0.t -> Ofday.t -> Core_kernel__.Date0.t * Ofday.t

It's unspecified what happens if the given date/ofday/zone correspond to more than one date/ofday pair in the other zone.

val utc_offset : t -> zone:Zone.t -> Span.t
Other string conversions

The {to,of}_string functions in Time convert to UTC time, because a local time zone is not necessarily available. They are generous in what they will read in.

include Interfaces.Stringable with type t := t
val of_string : string -> t
val to_string : t -> string
val to_filename_string : t -> zone:Zone.t -> Base.String.t

to_filename_string t ~zone converts t to string with format YYYY-MM-DD_HH-MM-SS.mmm which is suitable for using in filenames.

val of_filename_string : Base.String.t -> zone:Zone.t -> t

of_filename_string s ~zone converts s that has format YYYY-MM-DD_HH-MM-SS.mmm into time.

val to_string_trimmed : t -> zone:Zone.t -> Base.String.t

Same as to_string_abs, but removes trailing seconds and milliseconds if they are 0

val to_sec_string : t -> zone:Zone.t -> Base.String.t

Same as to_string_abs, but without milliseconds

val of_localized_string : zone:Zone.t -> Base.String.t -> t

of_localized_string ~zone str read in the given string assuming that it represents a time in zone and return the appropriate Time.t

val of_string_gen : default_zone:(Base.Unit.t -> Zone.t) -> find_zone:(Base.String.t -> Zone.t) -> Base.String.t -> t

of_string_gen ~default_zone ~find_zone s attempts to parse s as a t, calling out to default_zone and find_zone as needed.

val to_string_abs : t -> zone:Zone.t -> Base.String.t

to_string_abs ~zone t returns a string that represents an absolute time, rather than a local time with an assumed time zone. This string can be round-tripped, even on a machine in a different time zone than the machine that wrote the string.

The string will display the date and of-day of zone together with zone as an offset from UTC.

to_string_abs_trimmed is the same as to_string_abs, but drops trailing seconds and milliseconds if they are 0.

Note that the difference between to_string and to_string_abs is not that one returns an absolute time and one doesn't, but that to_string_abs lets you specify the time zone, while to_string takes it to be the local time zone.

val to_string_abs_trimmed : t -> zone:Zone.t -> Base.String.t
val to_string_abs_parts : t -> zone:Zone.t -> Base.String.t Base.List.t
val to_string_iso8601_basic : t -> zone:Zone.t -> Base.String.t

to_string_iso8601_basic return a string representation of the following form: %Y-%m-%dT%H:%M:%S.%s%Z e.g. to_string_iso8601_basic ~zone:Time.Zone.utc epoch = "1970-01-01T00:00:00.000000Z"

val occurrence : [ `First_after_or_at | `Last_before_or_at ] -> t -> ofday:Ofday.t -> zone:Zone.t -> t

occurrence side time ~ofday ~zone returns a Time.t that is the occurrence of ofday (in the given zone) that is the latest occurrence (<=) time or the earliest occurrence (>=) time, according to side.

NOTE: If the given time converted to wall clock time in the given zone is equal to ofday then the t returned will be equal to the t given.

val next_multiple : ?can_equal_after:Base.Bool.t -> base:t -> after:t -> interval:Span.t -> Base.Unit.t -> t

next_multiple ~base ~after ~interval returns the smallest time of the form:

time = base + k * interval

where k >= 0 and time > after. It is an error if interval <= 0.

Supplying ~can_equal_after:true allows the result to satisfy time >= after.

module Stable : sig ... end
OCaml

Innovation. Community. Security.

GitHub Discord Twitter Peertube RSS
About
Changelog Releases Industrial Users Academic Users Why OCaml
Ecosystem
Packages Community Events OCaml Planet Jobs
Resources
Install OCaml Get Started Platform Tools Language Manual Standard Library API Books Exercises Papers OCaml Playground Logo
Policies
Carbon Footprint Governance Privacy Code of Conduct