How to convert a Date struct to an easily readable string?

Questions / Help
1

Hi!

My goal is to convert the Date struct to an easily-readable string version of that date.

For example:

~D[2000-01-15] would be converted to “January 15th, 2024”.

Does anyone know of a function or library that already does this?

Thanks!!!

2

The function you’re looking for is this one: Calendar.strftime/3

That will let you pass in the date and then a format string in which you can specify things like the full name of the month, date, etc.

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3

Suggestions on how to format the day of the month as an ordinal number?

Ex: August 1 as August 1st, August 2 as August 2nd, etc.

4

It could be implemented somewhere in Cldr.Calendars or Cldr.Numbers. If it isn’t, or if you’re not willing to add an extra dependency, writing your own implementation is straightforward:

def ending(day) when day in [1, 21, 31], do: "st"
def ending(day) when day in [2, 22], do: "nd"
def ending(day) when day in [3, 23], do: "rd"
def ending(_), do: "th"
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5

I’ve just realized that the version of this function without function overloading would look a bit cleaner. However, I miss this killer feature of Elixir so much when programming in other languages that I sometimes find myself overusing it. :smile:

6

Nah :slight_smile: The below is the real overusing of Elixir killer features:

defmodule DayEnding do
  Enum.each(1..31, fn
    day when div(day, 10) == 1 -> def ending(unquote(day)), do: "th"
    day when rem(day, 10) == 1 -> def ending(unquote(day)), do: "st"
    day when rem(day, 10) == 2 -> def ending(unquote(day)), do: "nd"
    day when rem(day, 10) == 3 -> def ending(unquote(day)), do: "rd"
    day -> def ending(unquote(day)), do: "th"
  end)
end
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7

ex_cldr_numbers can format ordinals, but CLDR does not maintain any date formats that include ordinal numbers.

iex> Cldr.Number.to_string 1, format: :ordinal
{:ok, "1st"}
iex> Cldr.Number.to_string 1, format: :ordinal, locale: :es
{:ok, "1.º"}
iex> Cldr.Number.to_string 1, format: :ordinal, locale: :zh
{:ok, "第1"}
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