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Module Time

Signature

include Core.Std.Time
module Ofday : sig .. end
module Span : sig .. end
module Zone : module type of Core.Zone with type t = Core.Zone.t
type t = Core.Time_internal.T.t

A fully qualified point in time, independent of timezone.

val t_of_sexp : Sexplib.Sexp.t -> t
val sexp_of_t : t -> Sexplib.Sexp.t
val __bin_read_t__ : (int -> t) Core_kernel.Std.Bin_prot.Read.reader
val get_sexp_zone : unit -> Zone.t

Sexp conversions use the local timezone by default. This can be overridden by calling set_sexp_zone.

val set_sexp_zone : Zone.t -> unit
include Core_kernel.Std.Hashable_binable with type t := t
type t
val hash : t -> int
module Table : Hashable.Hashtbl.S_binable with type key = t
include Core_kernel.Std.Comparable_binable with type t := t
include Comparable_intf.S_common
include Comparable_intf.Polymorphic_compare
include Polymorphic_compare_intf.Infix
type 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
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 Or_error.t
include Comparator.S with type t := t
type t
type comparator_witness
include Comparable_intf.Validate with type t := t
type t
val validate_lbound : min:t Maybe_bound.t -> t Validate.check
val validate_ubound : max:t Maybe_bound.t -> t Validate.check
val validate_bound : min:t Maybe_bound.t -> max:t Maybe_bound.t -> t Validate.check
include Comparable_intf.Map_and_set_binable with type t := t with type comparator_witness := comparator_witness
type t
include Comparator.S with type t := t
type t
type comparator_witness
include Core_kernel.Std.Robustly_comparable with type t := t
type 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
include Core_kernel.Std.Floatable with type t := t
type t
val of_float : float -> t
val to_float : t -> float
include Core_kernel.Std.Pretty_printer.S with type t := t
type t
val pp : Format.formatter -> t -> unit
include Core_kernel.Std.Stringable with type t := t
type t
val of_string : string -> t
val to_string : t -> string
values

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

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 -> bool

is_earlier and is_later are like using <., but easier to read.

val is_later : t -> than:t -> bool
Constants
Conversions

All these conversion functions use the current time zone. Unless marked _utc, in which case they use Universal Coordinated Time

val of_date_ofday : Core.Date0.t -> Ofday.t -> zone:Zone.t -> t
val to_date_ofday : t -> zone:Zone.t -> Core.Date0.t * Ofday.t
val to_date : t -> zone:Zone.t -> Core.Date0.t
val to_ofday : t -> zone:Zone.t -> Ofday.t
val of_date_ofday_precise : Core.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_precise : t -> zone:Zone.t -> Core.Date0.t * Ofday.t * [
| `Only
| `Also_at of t
| `Also_skipped of Core.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 convert : from_tz:Zone.t -> to_tz:Zone.t -> Core.Date0.t -> Ofday.t -> Core.Date0.t * Ofday.t
val utc_offset : t -> zone:Zone.t -> Span.t
Other string conversions
val to_filename_string : t -> zone:Zone.t -> string

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 : string -> 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_fix_proto : [
| `Utc
| `Local
] -> t -> string
val of_string_fix_proto : [
| `Utc
| `Local
] -> string -> t
val to_string_trimmed : t -> zone:Zone.t -> string

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

val to_sec_string : t -> zone:Zone.t -> string

Same as to_string_abs, but without milliseconds

val of_localized_string : zone:Zone.t -> string -> 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 to_string_abs : t -> zone:Zone.t -> string

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 -> string
val of_string_abs : string -> t

of_string_abs s is like of_string, but demands that s indicate the timezone the time is expressed in.

val t_of_sexp_abs : Core_kernel.Std.Sexp.t -> t

t_of_sexp_abs sexp as t_of_sexp, but demands that sexp indicate the timezone the time is expressed in.

Miscellaneous
val now : unit -> t
Returns the current time.
val pause : Span.t -> unit

pause span sleeps for span time.

val interruptible_pause : Span.t -> [
| `Ok
| `Remaining of Span.t
]

interruptible_pause span sleeps for span time unless interrupted (e.g. by delivery of a signal), in which case the remaining unslept portion of time is returned.

val pause_forever : unit -> Core_kernel.Std.never_returns

pause_forever sleeps indefinitely.

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 format : t -> string -> zone:Zone.t -> string

format t fmt formats the given time according to fmt, which follows the formatting rules given in 'man strftime'. The time is output in the given timezone.

      %Y - year (4 digits)
      %y - year (2 digits)
      %m - month
      %d - day
      %H - hour
      %M - minute
      %S - second

a common choice would be: %Y-%m-%d %H:%M:%S

val to_epoch : t -> float

to_epoch t returns the number of seconds since Jan 1, 1970 00:00:00 in UTC

of_epoch x returns the time x seconds after Jan 1, 1970 00:00:00 in UTC

val of_epoch : float -> t

of_epoch x returns the time x seconds after Jan 1, 1970 00:00:00 in UTC

val next_multiple : ?can_equal_after:bool -> base:t -> after:t -> interval:Span.t -> unit -> t
module Stable : sig .. end
include Extended_time
module Extended_date : sig .. end
module Extended_span : sig .. end