View Source Tempus (Tempus v0.15.0)

Tempus is a library to deal with timeslots.

It aims to be a fast yet easy to use implementation of a schedule of any type, including but not limited to free/busy time schedules.

The example of it might be a calendar software, where slots might be marked as free, or busy. It also allows simple arithmetics with schedules, like adding five days or subtracting 7 hours 30 minutes from now, considering busy slots.

Summary

Types

count()

Number of slots (:stream means lazy folding, unknown upfront)

direction()

Direction for slots navigation

option()

Navigation option

options()

Argument containing navigation options

slice_type()

The type defining how slicing is to be applied. When :greedy, overlapping boundary slots would be included, :reluctant would take only those fully contained in the interval.

Functions

add(slots, origin \\ DateTime.utc_now(), amount_to_add, unit \\ :second)

Adds an amount of units to the origin, considering slots given.

days_add(slots, opts \\ [])

Returns the reversed list of free days after origin.

days_ago(slots, origin, count) deprecated

Returns the reversed list of free days after origin.

days_ahead(slots, origin, count) deprecated

Returns the reversed list of free days after origin.

drop_while(slots, fun)

Drops slots at the beginning of the %Slots{} struct while fun returns a truthy value.

free?(slots, origin)

Checks whether the slot is disjoined against slots.

guess(input)

Helper to instantiate slot from any known format, by wrapping the argument.

guess(from, to)

Helper to instantiate slot from any known format, by joining the arguments.

new(data)

Creates the new instance of Tempus.Slots.t(Tempus.Slots.Stream.t()) backed by stream.

next_busy(slots, opts \\ []) deprecated

Returns the next busy slot from the slots passed as a first argument, that immediately follows origin. If slots are overlapped, the overlapped one gets returned.

next_free(slots, opts \\ []) deprecated

Returns the next free slot from the slots passed as a first argument, that immediately follows origin. If slots are overlapped, the overlapped one gets returned.

parse_cron(origin, cron)

Creates a Tempus.Slots.Stream.t() slots stream by a cron-like definition.

slice(slots, from, to, type \\ :reluctant)

Slices the %Slots{} based on origins from and to and an optional type (default: :reluctant.) Returns sliced %Slots{} back.

slot(from, to)

See Tempus.Slot.new/2.

slot!(from, to)

See Tempus.Slot.new!/2.

slots(enum)

Syntactic sugar for |> Enum.into(%Slots{}).

stream(start_value, next_fun)

Syntactic sugar for Tempus.Slots.Stream.iterate/3 with default options return_as: :slots, join: true.

take(slots, count)

Takes an amount of elements from the beginning of the Tempus.Slots structure, returning Tempus.Slots.List instance.

take_while(slots, fun)

Takes slots at the beginning of the %Slots{} struct while fun returns a truthy value.

Types

count()

@type count() :: :infinity | :stream | non_neg_integer()

Number of slots (:stream means lazy folding, unknown upfront)

direction()

@type direction() :: :fwd | :bwd

Direction for slots navigation

option()

@type option() ::
  {:origin, Tempus.Slot.origin()}
  | {:count, count() | neg_integer()}
  | {:direction, direction()}

Navigation option

options()

@type options() :: [option()]

Argument containing navigation options

slice_type()

@type slice_type() :: :greedy | :reluctant

The type defining how slicing is to be applied. When :greedy, overlapping boundary slots would be included, :reluctant would take only those fully contained in the interval.

Functions

add(slots, origin \\ DateTime.utc_now(), amount_to_add, unit \\ :second)

@spec add(
  slots :: Tempus.Slots.t(),
  origin :: DateTime.t(),
  amount_to_add :: integer(),
  unit :: System.time_unit()
) :: DateTime.t()

Adds an amount of units to the origin, considering slots given.

Examples

iex> slots = [
...>   ~D|2020-08-07|,
...>   ~D|2020-08-10|,
...>   ~D|2020-08-11|,
...>   ~D|2020-08-14|
...> ] |> Enum.into(Tempus.Slots.new(:stream, []))
iex> Tempus.add(slots, ~U|2020-08-11 23:00:00Z|, 0, :second)
~U[2020-08-12 00:00:00Z]
iex> Tempus.add(slots, ~U|2020-08-12 01:00:00Z|, 0, :second)
~U[2020-08-12 01:00:00Z]
iex> Tempus.add(slots, ~U|2020-08-11 23:00:00Z|, -10*60+1, :second)
~U[2020-08-09 23:50:00Z]
iex> Tempus.add(slots, ~U|2020-08-12 00:09:00Z|, -10*60, :second)
~U[2020-08-09 23:59:00Z]
iex> Tempus.add(slots, ~U|2020-08-12 00:10:00Z|, -10*60, :second)
~U[2020-08-12 00:00:00Z]
iex> Tempus.add(slots, ~U|2020-08-12 00:10:00Z|, -10*60-1, :second)
~U[2020-08-09 23:59:59Z]
iex> Tempus.add(slots, ~U|2020-08-11 23:00:00Z|, 10*60, :second)
~U[2020-08-12 00:10:00Z]
iex> Tempus.add(slots, ~U|2020-08-12 00:00:00Z|, 10*60, :second)
~U[2020-08-12 00:10:00Z]
iex> Tempus.add(slots, ~U|2020-08-09 23:55:00Z|, 10*60, :second)
~U[2020-08-12 00:05:00Z]
iex> Tempus.add(slots, ~U|2020-08-08 23:55:00Z|, 10*60, :second)
~U[2020-08-09 00:05:00Z]
iex> Tempus.add(slots, ~U|2020-08-06 23:55:00Z|, 2*3600*24 + 10*60, :second)
~U[2020-08-12 00:05:00Z]

iex> slots = Tempus.Slots.new(:stream, [])
iex> Tempus.add(slots, ~U|2020-08-12 01:00:00Z|, 0, :second)
~U[2020-08-12 01:00:00Z]
iex> Tempus.add(slots, ~U|2020-08-11 23:00:00Z|, 5*60+1, :second)
~U[2020-08-11 23:05:01.000000Z]
iex> Tempus.add(slots, ~U|2020-08-11 23:00:00Z|, -10*60+1, :second)
~U[2020-08-11 22:50:01Z]

iex> slots = Tempus.Slots.new(:list, [])
iex> Tempus.add(slots, ~U|2020-08-12 01:00:00Z|, 0, :second)
~U[2020-08-12 01:00:00Z]
iex> Tempus.add(slots, ~U|2020-08-11 23:00:00Z|, 5*60+1, :second)
~U[2020-08-11 23:05:01Z]
iex> Tempus.add(slots, ~U|2020-08-11 23:00:00Z|, -10*60+1, :second)
~U[2020-08-11 22:50:01Z]
iex> slots |> Tempus.add(1) |> DateTime.to_date()
Date.utc_today()

days_add(slots, opts \\ [])

(since 0.2.0)

@spec days_add(slots :: Tempus.Slots.t(), opts :: options()) :: [Date.t()]

Returns the reversed list of free days after origin.

Examples

iex> slots = [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|)
...> ] |> Enum.into(%Tempus.Slots{})
iex> Tempus.days_add(slots, origin: ~D|2020-08-07|, count: 3) |> hd()
~D|2020-08-12|
iex> Tempus.days_add(slots, origin: ~D|2020-08-07|, count: 3, direction: :fwd) |> hd()
~D|2020-08-12|
iex> Tempus.days_add(slots, origin: ~D|2020-08-07|, count: -3, direction: :bwd) |> hd()
~D|2020-08-12|
iex> Tempus.days_add(slots, origin: ~D|2020-08-12|, count: -4) |> hd()
~D|2020-08-06|
iex> Tempus.days_add(slots, origin: ~D|2020-08-12|, count: 4, direction: :bwd) |> hd()
~D|2020-08-06|
iex> Tempus.days_add(slots, origin: ~D|2020-08-12|, count: -4, direction: :fwd) |> hd()
~D|2020-08-06|

days_ago(slots, origin, count)

This function is deprecated. Use days_add/2 with negative count or `:bwd` forth parameter instead.

@spec days_ago(slots :: Tempus.Slots.t(), origin :: Date.t(), count :: integer()) :: [
  Date.t()
]

Returns the reversed list of free days after origin.

Examples

iex> slots = [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|)
...> ] |> Enum.into(%Tempus.Slots{})
iex> Tempus.days_ago(slots, ~D|2020-08-07|, 0)
[~D|2020-08-06|]
iex> Tempus.days_ago(slots, ~D|2020-08-12|, 4) |> hd()
~D|2020-08-06|

days_ahead(slots, origin, count)

This function is deprecated. Use days_add/2 instead.

@spec days_ahead(slots :: Tempus.Slots.t(), origin :: Date.t(), count :: integer()) ::
  [Date.t()]

Returns the reversed list of free days after origin.

Examples

iex> slots = [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|)
...> ] |> Enum.into(%Tempus.Slots{})
iex> Tempus.days_ahead(slots, ~D|2020-08-07|, 0)
[~D|2020-08-08|]
iex> Tempus.days_ahead(slots, ~D|2020-08-07|, 3) |> hd()
~D|2020-08-12|

drop_while(slots, fun)

(since 0.7.0)

@spec drop_while(slots :: Tempus.Slots.t(), fun :: (Tempus.Slot.t() -> boolean())) ::
  Tempus.Slots.t()

Drops slots at the beginning of the %Slots{} struct while fun returns a truthy value.

Examples

iex> import Tempus.Guards
...> slots = [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|)
...> ] |> Enum.into(%Tempus.Slots{})
iex> slots
...> |> Tempus.drop_while(&is_slot_coming_before(&1, Tempus.Slot.wrap(~D|2020-08-09|)))
...> |> Enum.count()
1

free?(slots, origin)

@spec free?(slots :: Tempus.Slots.t(), slot :: Tempus.Slot.origin()) :: boolean()

Checks whether the slot is disjoined against slots.

Examples

iex> slots = [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|)
...> ] |> Enum.into(%Tempus.Slots{})
iex> Tempus.free?(slots, ~D|2020-08-07|)
false
iex> Tempus.free?(slots, ~D|2020-08-08|)
true
iex> Tempus.free?(slots, ~U|2020-08-09T23:59:59.999999Z|)
true
iex> Tempus.free?(slots, DateTime.add(~U|2020-08-09T23:59:59.999999Z|, 1, :microsecond))
false

guess(input)

@spec guess(input :: nil | binary()) :: {:ok, Tempus.Slot.t()} | {:error, any()}

Helper to instantiate slot from any known format, by wrapping the argument.

Examples

iex> Tempus.guess("2023-04-10")
{:ok, Tempus.Slot.wrap(~D[2023-04-10])}
iex> Tempus.guess(nil)
{:ok, %Tempus.Slot{from: nil, to: nil}}
iex> Tempus.guess("∞")
{:ok, %Tempus.Slot{from: nil, to: nil}}
iex> Tempus.guess("")
{:ok, %Tempus.Slot{from: nil, to: nil}}
iex> Tempus.guess("2023-04-10T10:00:00Z")
{:ok, Tempus.Slot.wrap(~U[2023-04-10T10:00:00Z])}
iex> Tempus.guess("10:00:00")
{:ok, Date.utc_today() |> DateTime.new!(Time.from_erl!({10, 0, 0})) |> Tempus.Slot.wrap()}
iex> Tempus.guess("20230410T235007.123+0230")
if Version.compare(System.version(), "1.14.0") == :lt do
  {:error, :invalid_format}
else
  {:ok, Tempus.Slot.wrap(~U[2023-04-10T21:20:07.123Z])}
end
iex> Tempus.guess("2023-04-10-15")
{:error, :invalid_format}

guess(from, to)

@spec guess(from :: nil | binary(), to :: nil | binary()) ::
  {:ok, Tempus.Slot.t()} | {:error, any()}

Helper to instantiate slot from any known format, by joining the arguments.

Examples

iex> import Tempus.Sigils
iex> Tempus.guess("2023-04-10", "2023-04-12")
{:ok, ~I[2023-04-10 00:00:00.000000Z|2023-04-12 23:59:59.999999Z]}
iex> Tempus.guess("2023-04-10", nil)
{:ok, ~I[2023-04-10 00:00:00.000000Z|2023-04-10T23:59:59.999999Z]}
iex> Tempus.guess("2023-04-10T10:00:00Z", "2023-04-12")
{:ok, ~I[2023-04-10 10:00:00Z|2023-04-12 23:59:59.999999Z]}
iex> Tempus.guess("20230410T235007.123+0230", "2023-04-12")
if Version.compare(System.version(), "1.14.0") == :lt do
  {:error, {:invalid_arguments, [from: :invalid_format]}}
else
  {:ok, ~I[2023-04-10 21:20:07.123Z|2023-04-12 23:59:59.999999Z]}
end
iex> Tempus.guess("2023-04-10", :ok)
{:error, {:invalid_arguments, [to: :invalid_argument]}}
iex> Tempus.guess(:ok, "2023-04-10")
{:error, {:invalid_arguments, [from: :invalid_argument]}}
iex> Tempus.guess("2023-04-10-15", :ok)
{:error, {:invalid_arguments, [from: :invalid_format, to: :invalid_argument]}}
iex> Tempus.guess("2023-20-40", "10:70:80")
{:error, {:invalid_arguments, [from: :invalid_date, to: :invalid_time]}}

new(data)

@spec new(data :: Tempus.Slots.container()) :: Tempus.Slots.t(Tempus.Slots.Stream)

Creates the new instance of Tempus.Slots.t(Tempus.Slots.Stream.t()) backed by stream.

This is a convinience wrapper for Tempus.Slots.new(:stream, data).

next_busy(slots, opts \\ [])

This function is deprecated. Use `slice/3` instead.

@spec next_busy(Tempus.Slots.t(), options()) ::
  [Tempus.Slot.t()] | Tempus.Slot.t() | nil | no_return()

Returns the next busy slot from the slots passed as a first argument, that immediately follows origin. If slots are overlapped, the overlapped one gets returned.

Examples

iex> slots = [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|)
...> ] |> Enum.into(%Tempus.Slots{})
iex> Tempus.next_busy(slots, origin: %Tempus.Slot{from: ~U|2020-08-08 23:00:00Z|, to: ~U|2020-08-09 12:00:00Z|})
%Tempus.Slot{from: ~U[2020-08-10 00:00:00.000000Z], to: ~U[2020-08-10 23:59:59.999999Z]}
iex> Tempus.next_busy(slots, origin: %Tempus.Slot{from: ~U|2020-08-07 11:00:00Z|, to: ~U|2020-08-07 12:00:00Z|}, count: 2) |> hd()
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-07 23:59:59.999999Z]}
iex> Tempus.next_busy(slots, origin: %Tempus.Slot{from: ~U|2020-08-07 11:00:00Z|, to: ~U|2020-08-08 12:00:00Z|})
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-07 23:59:59.999999Z]}
iex> Tempus.next_busy(slots, origin: %Tempus.Slot{from: ~U|2020-08-07 11:00:00Z|, to: ~U|2020-08-10 12:00:00Z|})
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-07 23:59:59.999999Z]}
iex> Tempus.next_busy(slots, origin: ~D|2020-08-07|)
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-07 23:59:59.999999Z]}
iex> Tempus.next_busy(slots, origin: ~D|2020-08-08|)
%Tempus.Slot{from: ~U[2020-08-10 00:00:00.000000Z], to: ~U[2020-08-10 23:59:59.999999Z]}
iex> Tempus.next_busy(slots, origin: ~D|2020-08-08|, direction: :bwd)
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-07 23:59:59.999999Z]}
iex> Tempus.next_busy(slots, origin: ~D|2020-08-10|, direction: :bwd)
%Tempus.Slot{from: ~U[2020-08-10 00:00:00.000000Z], to: ~U[2020-08-10 23:59:59.999999Z]}
iex> Tempus.next_busy(slots, origin: ~D|2020-08-10|, direction: :bwd, count: :infinity)
slots
iex> Tempus.next_busy(slots, origin: ~D|2020-08-10|, count: 3.1415)
** (Tempus.ArgumentError) invalid argument: expected ‹Elixir.Integer›, got: ‹3.1415›
iex> Tempus.next_busy(slots, origin: ~D|2020-08-10|, direction: :bwd, count: 2)
Enum.to_list(slots)
iex> Tempus.next_busy(slots, origin: ~D|2020-08-10|, direction: :bwd, count: 1)
Enum.drop(slots, 1)
iex> Tempus.next_busy(slots, origin: %Tempus.Slot{from: ~U|2020-08-11 11:00:00Z|, to: ~U|2020-08-11 12:00:00Z|})
nil
iex> Tempus.next_busy(slots, origin: %Tempus.Slot{from: ~U|2020-08-06 11:00:00Z|, to: ~U|2020-08-06 12:00:00Z|}, direction: :bwd)
nil
iex> Tempus.next_busy(%Tempus.Slots{})
nil

next_free(slots, opts \\ [])

This function is deprecated. Use `slice/3` instead.

@spec next_free(Tempus.Slots.t(), options()) ::
  [Tempus.Slot.t()] | Tempus.Slot.t() | no_return()

Returns the next free slot from the slots passed as a first argument, that immediately follows origin. If slots are overlapped, the overlapped one gets returned.

Examples

iex> import Tempus.Sigils
iex> slots = [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|),
...>   Tempus.Slot.wrap(~D|2020-08-12|),
...>   Tempus.Slot.wrap(~D|2020-08-14|),
...>   Tempus.Slot.wrap(~D|2030-08-14|)
...> ] |> Enum.into(%Tempus.Slots{})
iex> Tempus.next_free(slots, origin: %Tempus.Slot{from: ~U|2020-08-08 23:00:00Z|, to: ~U|2020-08-09 12:00:00Z|})
~I[2020-08-08 00:00:00.000000Z → 2020-08-09 23:59:59.999999Z]
iex> Tempus.next_free(slots, origin: %Tempus.Slot{from: ~U|2020-08-06 11:00:00Z|, to: ~U|2020-08-06 12:00:00Z|})
~I[∞ → 2020-08-06 23:59:59.999999Z]nu
iex> Tempus.next_free(slots, origin: ~U|2020-08-13 01:00:00.000000Z|)
~I[2020-08-13 00:00:00.000000Z → 2020-08-13 23:59:59.999999Z]
iex> Tempus.next_free(slots, origin: ~D|2020-08-13|)
~I[2020-08-13 00:00:00.000000Z → 2020-08-13 23:59:59.999999Z]
iex> Tempus.next_free(slots, origin: ~D|2020-08-14|)
~I[2020-08-15 00:00:00.000000Z → 2030-08-13 23:59:59.999999Z]
iex> Tempus.next_free(slots)
~I[2020-08-15 00:00:00.000000Z → 2030-08-13 23:59:59.999999Z]

parse_cron(origin, cron)

@spec parse_cron(
  origin :: Tempus.Slot.origin() | nil,
  cron :: binary() | Tempus.Crontab.t()
) ::
  Tempus.Slots.t(Stream)

Creates a Tempus.Slots.Stream.t() slots stream by a cron-like definition.

Examples

iex> import Tempus.Sigils
iex> ~U[2024-06-07 12:00:00Z] |> Tempus.parse_cron("10-30/15 */4 1 */1 6,7") |> Enum.take(5)
[
  ~I(2024-06-08T00:10:00Z → 2024-06-08T00:10:00Z),
  ~I(2024-06-08T00:25:00Z → 2024-06-08T00:25:00Z),
  ~I(2024-06-08T04:10:00Z → 2024-06-08T04:10:00Z),
  ~I(2024-06-08T04:25:00Z → 2024-06-08T04:25:00Z),
  ~I(2024-06-08T08:10:00Z → 2024-06-08T08:10:00Z)
]

slice(slots, from, to, type \\ :reluctant)

(since 0.7.0)

@spec slice(
  slots :: Tempus.Slots.t(),
  from :: Tempus.Slots.locator(),
  to :: Tempus.Slots.locator(),
  type :: slice_type()
) :: Tempus.Slots.t()

Slices the %Slots{} based on origins from and to and an optional type (default: :reluctant.) Returns sliced %Slots{} back.

Examples

iex> slots = [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|)
...> ] |> Enum.into(%Tempus.Slots{})
iex> slots |> Tempus.slice(~D|2020-08-07|, ~D|2020-08-11|) |> Enum.count()
1

slot(from, to)

See Tempus.Slot.new/2.

slot!(from, to)

See Tempus.Slot.new!/2.

slots(enum)

Syntactic sugar for |> Enum.into(%Slots{}).

Examples

iex> [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|),
...>   Tempus.Slot.wrap(~D|2020-08-12|)
...> ] |> Tempus.slots()
%Tempus.Slots{slots: %Tempus.Slots.List{slots: [
    %Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-07 23:59:59.999999Z]},
    %Tempus.Slot{from: ~U[2020-08-10 00:00:00.000000Z], to: ~U[2020-08-10 23:59:59.999999Z]},
    %Tempus.Slot{from: ~U[2020-08-12 00:00:00.000000Z], to: ~U[2020-08-12 23:59:59.999999Z]}]}}

stream(start_value, next_fun)

@spec stream(Tempus.Slot.origin(), (Tempus.Slot.t() -> Tempus.Slot.t())) ::
  Tempus.Slots.t(Tempus.Slots.Stream)

Syntactic sugar for Tempus.Slots.Stream.iterate/3 with default options return_as: :slots, join: true.

Examples

iex> import Tempus.Sigils
...> Tempus.stream(~D|2024-01-20|, &Tempus.Slot.shift(&1, by: rem(&1.from.day, 2) + 1, unit: :day)) |> Enum.take(3)
[~I(2024-01-20T00:00:00.000000Z → 2024-01-21T23:59:59.999999Z),
 ~I(2024-01-23T00:00:00.000000Z → 2024-01-23T23:59:59.999999Z),
 ~I(2024-01-25T00:00:00.000000Z → 2024-01-25T23:59:59.999999Z)]

take(slots, count)

@spec take(Tempus.Slots.t(), non_neg_integer()) :: Tempus.Slots.t(Tempus.Slots.List)

Takes an amount of elements from the beginning of the Tempus.Slots structure, returning Tempus.Slots.List instance.

If amount is 0, it returns Tempus.Slots.List.new/0.

Examples

iex> import Tempus.Sigils
...> Tempus.stream(~D|2024-01-20|, &Tempus.Slot.shift(&1, by: rem(&1.from.day, 2) + 1, unit: :day)) |> Tempus.take(3)
Tempus.Slots.new(:list, [~I(2024-01-20T00:00:00.000000Z → 2024-01-21T23:59:59.999999Z),
                         ~I(2024-01-23T00:00:00.000000Z → 2024-01-23T23:59:59.999999Z),
                         ~I(2024-01-25T00:00:00.000000Z → 2024-01-25T23:59:59.999999Z)])

take_while(slots, fun)

(since 0.7.0)

@spec take_while(slots :: Tempus.Slots.t(), fun :: (Tempus.Slot.t() -> boolean())) ::
  Tempus.Slots.t()

Takes slots at the beginning of the %Slots{} struct while fun returns a truthy value.

Examples

iex> import Tempus.Guards
...> slots = [
...>   Tempus.Slot.wrap(~D|2020-08-07|),
...>   Tempus.Slot.wrap(~D|2020-08-10|)
...> ] |> Enum.into(%Tempus.Slots{})
iex> slots
...> |> Tempus.take_while(&is_slot_coming_before(&1, Tempus.Slot.wrap(~D|2020-08-09|)))
...> |> Enum.count()
1