module type S =
  sig
    type t
    module Date : Date_sig.S
    module Time : Time_sig.S
    type day = Date.day = Sun | Mon | Tue | Wed | Thu | Fri | Sat
    type month =
      Date.month =
        Jan
      | Feb
      | Mar
      | Apr
      | May
      | Jun
      | Jul
      | Aug
      | Sep
      | Oct
      | Nov
      | Dec
    type year = Date.year
    type second = Time.second
    type field =
        [ `Day | `Hour | `Minute | `Month | `Second | `Week | `Year ]
    val make : int -> int -> int -> int -> int -> second -> t
    val lmake :
      year:int ->
      ?month:int ->
      ?day:int -> ?hour:int -> ?minute:int -> ?second:second -> unit -> t
    val create : Date.t -> Time.t -> t
    val now : unit -> t
    val from_jd : float -> t
    val from_mjd : float -> t
    val convert : t -> Time_Zone.t -> Time_Zone.t -> t
    val to_gmt : t -> t
    val from_gmt : t -> t
    val days_in_month : t -> int
    val day_of_week : t -> day
    val day_of_month : t -> int
    val day_of_year : t -> int
    val week : t -> int
    val month : t -> month
    val year : t -> int
    val to_jd : t -> float
    val to_mjd : t -> float
    val hour : t -> int
    val minute : t -> int
    val second : t -> second
    val equal : t -> t -> bool
    val compare : t -> t -> int
    val hash : t -> int
    val is_leap_day : t -> bool
    val is_gregorian : t -> bool
    val is_julian : t -> bool
    val is_pm : t -> bool
    val is_am : t -> bool
    val to_unixtm : t -> Unix.tm
    val from_unixtm : Unix.tm -> t
    val to_unixfloat : t -> float
    val from_unixfloat : float -> t
    val from_date : Date.t -> t
    val to_date : t -> Date.t
    val to_time : t -> Time.t
    module Period :
      sig
        type t
        val empty : t
        val add : t -> t -> t
        val sub : t -> t -> t
        val opp : t -> t
        val equal : t -> t -> bool
        val compare : t -> t -> int
        val hash : t -> int
        val make : int -> int -> int -> int -> int -> second -> t
        val lmake :
          ?year:int ->
          ?month:int ->
          ?day:int -> ?hour:int -> ?minute:int -> ?second:second -> unit -> t
        val year : int -> t
        val month : int -> t
        val week : int -> t
        val day : int -> t
        val hour : int -> t
        val minute : int -> t
        val second : second -> t
        val from_date : Date.Period.t -> t
        val from_time : Time.Period.t -> t
        val to_date : t -> Date.Period.t
        exception Not_computable
        val to_time : t -> Time.Period.t
        val ymds : t -> int * int * int * second
      end
    val add : t -> Period.t -> t
    val sub : t -> t -> Period.t
    val rem : t -> Period.t -> t
    val next : t -> field -> t
    val prev : t -> field -> t
  end