How to format datetime to show for example "5th of January 2020"?

Questions
1

Hello!

I have read through the documentation of datetime in typst here (Datetime Type – Typst Documentation) and gotten to this:

datetime.today().display("[day] of [month repr:long] [year]")

image

But how can I get it to do correctly, the 2nd, 3rd, 10th, 15th of a month etc. so it comes out as 5th of January 2020 for example?

Kind regards

2

You will have to manually find the appropriate suffix
Something like this should work for your needs

#let my-date(..args) = {
  let date = if args.pos().len() == 0 {
    datetime.today()
  } else {
    args.pos().first()
  }
  let day = date.day()
  let suffix = if day in (11, 12, 13) { "th" } else {
    ("st", "nd", "rd").at(calc.rem(day - 1, 10), default: "th")
  }
  date.display("[day padding:none]" + suffix + " of [month repr:long] [year]")
}
Today: #my-date()\
Custom date: #my-date(datetime(year: 2020, month: 1, day: 5))

EDIT: implemented Eric’s fix

1 Like
3

Watch out when determining the suffix, you currently have an off-by-one error at the start of the month, and wrong suffixes for 21, 22, 23 and 31 ;)

Something like this should do it

let suffix = if day in (11, 12, 13) { "th" } else {
  ("st", "nd", "rd").at(calc.rem(day - 1, 10), default: "th")
}
1 Like
4

:man_facepalming: :man_facepalming: :man_facepalming: indeed, thank you for your correction :sweat_smile:

5

This errors with 10 though:

my-date(datetime(year: 2020, month: 1, day: 10))

image

Any suggestions :) ?

EDIT: ChatGPT believes this to be a solution which works according to my test:

  let my_date(..args) = {
    // Determine the date, defaulting to today if no argument is provided.
    let date = if args.pos().len() == 0 {
      datetime.today()
    } else {
      args.pos().first()
    }
    
    // Calculate the day and determine the correct suffix.
    let day = date.day()
    let suffix = if day in (11, 12, 13) {
      "th"
    } else if calc.rem(day, 10) == 1 {
      "st"
    } else if calc.rem(day, 10) == 2 {
      "nd"
    } else if calc.rem(day, 10) == 3 {
      "rd"
    } else {
      "th"
    }

  // Display the formatted date.
  date.display("[day padding:none]" + suffix + " of [month repr:long] [year]")
}
6

Oops, you’re right, it should be calc.rem(day - 1, 10) instead of calc.rem(day, 10) - 1, I have edited my above reply. Your more explicit code by ChatGPT also works of course!

1 Like
7

Thank you Eric, I have used your fix with the solution provided above

Thank you to both of you! :)

8

May I suggest the nth package? :slight_smile:

then you don’t have to do this logic yourself:

#import "@preview/nth:1.0.1": *

#let my-date(date) = nth(date.day()) + date.display(" of [month repr:long] [year]")

Today: #my-date(datetime.today())\
Custom date: #my-date(datetime(year: 2020, month: 1, day: 5))

or replace nth with nths if you want superscript

3 Likes