package timezone

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Module type Timezone.Extend_zoneSource

Sourcetype t
Sourceval t_sexp_grammar : t Sexplib0.Sexp_grammar.t
include Core.Identifiable.S with type t := t
include Bin_prot.Binable.S with type t := t
include Bin_prot.Binable.S_only_functions with type t := t
Sourceval bin_size_t : t Bin_prot.Size.sizer
Sourceval bin_write_t : t Bin_prot.Write.writer
Sourceval bin_read_t : t Bin_prot.Read.reader
Sourceval __bin_read_t__ : (int -> t) Bin_prot.Read.reader

This function only needs implementation if t exposed to be a polymorphic variant. Despite what the type reads, this does *not* produce a function after reading; instead it takes the constructor tag (int) before reading and reads the rest of the variant t afterwards.

Sourceval bin_shape_t : Bin_prot.Shape.t
include Ppx_hash_lib.Hashable.S with type t := t
include Sexplib0.Sexpable.S with type t := t
Sourceval t_of_sexp : Sexplib0.Sexp.t -> t
include Ppx_compare_lib.Comparable.S with type t := t
include Ppx_hash_lib.Hashable.S with type t := t
Sourceval sexp_of_t : t -> Sexplib0.Sexp.t
include Base.Stringable.S with type t := t
Sourceval of_string : string -> t
Sourceval to_string : t -> string
include Base.Pretty_printer.S with type t := t
Sourceval pp : Base.Formatter.t -> t -> unit
include Core.Comparable.S_binable with type t := t
include Base.Comparable.S with type t := t
include Base.Comparisons.S with type t := t
include Base.Comparisons.Infix with type t := t
Sourceval (>=) : t -> t -> bool
Sourceval (<=) : t -> t -> bool
Sourceval (=) : t -> t -> bool
Sourceval (>) : t -> t -> bool
Sourceval (<) : t -> t -> bool
Sourceval (<>) : t -> t -> bool
Sourceval equal : t -> t -> bool
Sourceval 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.

Sourceval min : t -> t -> t
Sourceval max : t -> t -> t
Sourceval 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 ~compare:ascending and List.sort ~cmp:descending, since they cause the list to be sorted in ascending or descending order, respectively.

Sourceval descending : t -> t -> int
Sourceval between : t -> low:t -> high:t -> bool

between t ~low ~high means low <= t <= high

Sourceval 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).

Sourceval clamp : t -> min:t -> max:t -> t Base.Or_error.t
include Base.Comparator.S with type t := t
Sourcetype comparator_witness
Sourceval validate_lbound : min:t Core.Maybe_bound.t -> t Validate.check
Sourceval validate_ubound : max:t Core.Maybe_bound.t -> t Validate.check
Sourceval validate_bound : min:t Core.Maybe_bound.t -> max:t Core.Maybe_bound.t -> t Validate.check
include Core.Comparator.S with type t := t with type comparator_witness := comparator_witness
include Core.Hashable.S_binable with type t := t
include Ppx_hash_lib.Hashable.S with type t := t
Sourceval hash_fold_t : Base.Hash.state -> t -> Base.Hash.state
Sourceval hashable : t Base.Hashable.t
include Diffable.S_atomic with type t := t
Sourcemodule Diff : sig ... end
Sourceval find : string -> t option

find name looks up a t by its name and returns it. This also accepts some aliases, including:

  • chi -> America/Chicago
  • nyc -> America/New_York
  • hkg -> Asia/Hong_Kong
  • ldn -> Europe/London
  • lon -> Europe/London
  • tyo -> Asia/Tokyo
Sourceval find_exn : string -> t
Sourceval local : t Core.Lazy.t

local is the machine's local timezone, as determined from the TZ environment variable or the /etc/localtime file. It is computed from the state of the process environment and on-disk tzdata database at some unspecified moment prior to its first use, so its value may be unpredictable if that state changes during program operation. Arguably, changing the timezone of a running program is a problematic operation anyway -- most people write code assuming the clock doesn't suddenly jump several hours without warning.

Note that any function using this timezone can throw an exception if the TZ environment variable is misconfigured or if the appropriate timezone files can't be found because of the way the box is configured. We don't sprinkle _exn all over all the names in this module because such misconfiguration is quite rare.

Sourceval initialized_zones : unit -> (string * t) list

initialized_zones () returns a sorted list of time zone names that have been loaded from disk thus far.

Low-level functions

The functions below are lower level and should be used more rarely.

Sourceval init : unit -> unit

init () pre-load all available time zones from disk, this function has no effect if it is called multiple times. Time zones will otherwise be loaded at need from the disk on the first call to find/find_exn.