The type of a time-zone.
bin_io and sexp representations of Zone.t are the name of the zone, and not the full data that is read from disk when Zone.find is called. The full Zone.t is reconstructed on the receiving/reading side by reloading the zone file from disk. Any zone name that is accepted by find
is acceptable in the bin_io and sexp representations.
val sexp_of_t : t -> Ppx_sexp_conv_lib.Sexp.t
val compare : t -> t -> Base.Int.t
val input_tz_file : zonename:Base.String.t -> filename:Base.String.t -> t
input_tz_file ~zonename ~filename
read in filename
and return t
with name t
= zonename
val likely_machine_zones : Base.String.t Base.List.t Base.Ref.t
likely_machine_zones
is a list of zone names that will be searched first when trying to determine the machine zone of a box. Setting this to a likely set of zones for your application will speed the very first use of the local timezone.
val of_utc_offset : hours:Base.Int.t -> t
of_utc_offset offset
returns a timezone with a static UTC offset (given in hours).
val utc : t
utc
the UTC time zone. Included for convenience
val name : t -> Base.String.t
val original_filename : t -> Base.String.t Base.Option.t
original_filename t
return the filename t
was loaded from (if any)
val digest : t -> Core_kernel.Md5.t Base.Option.t
digest t
return the MD5 digest of the file the t was created from (if any)
val reset_transition_cache : t -> Base.Unit.t
For performance testing only; reset_transition_cache t
resets an internal cache in t
used to speed up repeated lookups of the same clock shift transition.
module Index : sig ... end
A time zone index refers to a range of times delimited by DST transitions at one or both ends. Every time belongs to exactly one such range. The times of DST transitions themselves belong to the range for which they are the lower bound.
val index : t -> Base.Float.t -> Index.t
Gets the index of a time.
val index_of_date_and_ofday : t -> Base.Float.t -> Index.t
val index_offset_from_utc_exn : t -> Index.t -> Base.Float.t
Gets the UTC offset of times in a specific range.
This can raise if you use an Index.t
that is out of bounds for this t
.
val index_abbreviation_exn : t -> Index.t -> Base.String.t
index_abbreviation_exn t index
returns the abbreviation name (such as EDT, EST, JST) of given zone t
for the range of index
. This string conversion is one-way only, and cannot reliably be turned back into a t
. This function reads and writes the zone's cached index. Raises if index
is out of bounds for t
.
val index_has_prev_clock_shift : t -> Index.t -> Base.Bool.t
Accessors for the DST transitions delimiting the start and end of a range, if any. The _exn
accessors raise if there is no such transition. These accessors are split up to increase performance and improve allocation; they are intended as a low-level back-end for commonly-used time conversion functions. See Time.Zone
and Time_ns.Zone
for higher-level accessors that return an optional tuple for clock shifts in either direction.
val index_prev_clock_shift_time_exn : t -> Index.t -> Base.Float.t
val index_prev_clock_shift_amount_exn : t -> Index.t -> Base.Float.t
val index_has_next_clock_shift : t -> Index.t -> Base.Bool.t
val index_next_clock_shift_time_exn : t -> Index.t -> Base.Float.t
val index_next_clock_shift_amount_exn : t -> Index.t -> Base.Float.t
val abbreviation : t -> Base.Float.t -> Base.String.t
abbreviation t time
returns the abbreviation name (such as EDT, EST, JST) of given zone t
at time
. This string conversion is one-way only, and cannot reliably be turned back into a t
. This function reads and writes the zone's cached index.
val absolute_time_of_date_and_ofday : t -> Base.Float.t -> Base.Float.t
absolute_time_of_date_and_ofday
and date_and_ofday_of_absolute_time
convert between absolute times and date + ofday forms. These are low level functions not intended for most clients. These functions read and write the zone's cached index.
val date_and_ofday_of_absolute_time : t -> Base.Float.t -> Base.Float.t
val next_clock_shift : t -> strictly_after:Base.Float.t -> (Base.Float.t * Base.Float.t) Base.Option.t
Takes a Time.t
and returns the next Time.t
strictly after it, if any, that the time zone UTC offset changes, and by how much it does so.
val prev_clock_shift : t -> at_or_before:Base.Float.t -> (Base.Float.t * Base.Float.t) Base.Option.t
As next_clock_shift
, but *at or before* the given time.
include Core_kernel.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
val bin_size_t : t Bin_prot.Size.sizer
val bin_write_t : t Bin_prot.Write.writer
val bin_read_t : t Bin_prot.Read.reader
val __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.
val bin_shape_t : Bin_prot.Shape.t
val bin_writer_t : t Bin_prot.Type_class.writer
val bin_reader_t : t Bin_prot.Type_class.reader
val bin_t : t Bin_prot.Type_class.t
val hash_fold_t : Base.Hash.state -> t -> Base.Hash.state
val hash : t -> Base.Hash.hash_value
include Ppx_sexp_conv_lib.Sexpable.S with type t := t
val t_of_sexp : Sexplib0.Sexp.t -> t
val sexp_of_t : t -> Sexplib0.Sexp.t
include Core_kernel.Identifiable.S_common with type t := t
val compare : t -> t -> Base.Int.t
val hash_fold_t : Base.Hash.state -> t -> Base.Hash.state
val hash : t -> Base.Hash.hash_value
val sexp_of_t : t -> Ppx_sexp_conv_lib.Sexp.t
include Base.Pretty_printer.S with type t := t
val pp : Base.Formatter.t -> t -> unit
include Core_kernel.Comparable.S_binable with type t := t
include Base.Comparable.S with type t := t
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
.
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.
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
val comparator : (t, comparator_witness) Base.Comparator.comparator
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 Replace_polymorphic_compare : sig ... end
include Core_kernel.Comparator.S with type t := t with type comparator_witness := comparator_witness
val comparator : (t, comparator_witness) Core_kernel.Comparator.comparator
module Map : Core_kernel.Map.S_binable with type Key.t = t with type Key.comparator_witness = comparator_witness
module Set : Core_kernel.Set.S_binable with type Elt.t = t with type Elt.comparator_witness = comparator_witness
include Core_kernel.Hashable.S_binable with type t := t
val hash_fold_t : Base.Hash.state -> t -> Base.Hash.state
val hash : t -> Base.Hash.hash_value
val hashable : t Core_kernel.Hashtbl.Hashable.t
module Table : Core_kernel.Hashtbl.S_binable with type key = t
module Hash_set : Core_kernel.Hash_set.S_binable with type elt = t
module Hash_queue : Core_kernel.Hash_queue.S with type key = t
val 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
- lon -> Europe/London
- tyo -> Asia/Tokyo
val find_exn : string -> t
val local : t Core_kernel.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.
val 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
val arg_type : t Core_kernel.Command.Arg_type.t