How to get month in ts-diff

[azzamsa]

I want to write a birthday app in different languages, one of them is Elisp.
The original implementation is written in Python.

The spec is:

• Given the input of year-month-day. return N years, N months, N days

The original implementation:

#!/usr/bin/env python3

import datetime
from dateutil.relativedelta import relativedelta

current_dt = datetime.datetime.now()
birth_date = datetime.datetime.strptime("1996-11-28", "%Y-%m-%d")
birth_date_formatted = birth_date.strftime("%A, %d %B %Y ")
diff = relativedelta(current_dt, birth_date)

print(f"Your age: {diff.years} years, {diff.months} months, {diff.days} days")

Which will display: Your age: 23 years, 9 months, 7 days

Given the same spec, I try to implement it in Elisp with ts.el:

ELISP> (ts-human-format-duration (ts-diff (ts-now) (ts-parse "1996-11-28")))
"23 years, 286 days, 11 hours, 2 minutes, 52 seconds"

how to get the month out of it, with the days being "9 months, 7 days"?.

---

I am aware that some time library doesn't return the month as well. Worrying about its flexibility and non-absolute answers. Such is one month: 1) 28 days, 30, or 31.

any opinion on this regarding ts.el?

[alphapapa]

The ambiguities you mention would make it difficult to give an accurate answer in terms of months, and accounting for various methods would be complicated, so it hasn't been implemented.

I suppose someone could port the Python relativedelta module to Elisp. If one were to do that, it would probably be best proposed as a patch to Emacs itself.

What do you think? Thanks.

[azzamsa]

Yes, the best thing we have is to dig deeper into https://github.com/dateutil/dateutil.

Rust, and Elisp doesn't have the simmiliar library. I don't check for Go-lang.