[Q/FR] Support for relative dates

[Fuco1]

Do you plan to support relative dates with a human readable instructions, like "last year" or "next month"... I would like to have something to parse these relative to today (or an argument passed in). But also it should understand input such as "2018" or "jan 2018" to give the specified intervals.

My current use-case is to make better reports for org-clock-budget where you could specify the intervals/periods with a simple query such as "last year" or "this week" and it will give you a report. This way users can view historical reports as well as the current ones.

It feels like it might be a separate package, "period" or something for returning the intervals specified by the query.

Edit: the inspiration comes from ledger https://github.com/ledger/ledger/blob/7c0ae5b02571e21f97d45f5d091cb78af9885713/src/times.cc and how it handles relative times. Maybe I will try to port it using ts as a backend.

[alphapapa]

I would like to, yes. The easiest solution would be to call out to GNU date, which has great natural language support, but it isn't available by default on Mac or BSD. I suppose we could port one of the nice Python libs, but that would be a lot of work.

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On Feb 26, 2019 10:28 AM, "Matus Goljer" ***@***.***> wrote: Do you plan to support relative dates with a human readable instructions, like "last year" or "next month"... I would like to have something to parse these relative to today (or an argument passed in). But also it should understand input such as "2018" or "jan 2018" to give the specified intervals. My current use-case is to make better reports for org-clock-budget where you could specify the intervals/periods with a simple query such as "last year" or "this week" and it will give you a report. This way users can view historical reports as well as the current ones. It feels like it might be a separate package, "period" or something for returning the intervals specified by the query. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#4>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAktFdKnQeqjCPkw2sgpEsfGSBZEKV1Hks5vRWDBgaJpZM4bSlLu> .

[alphapapa]

@Fuco1 FYI, I just updated this package, fixing all warnings, adding tests, adding docs, and submitting to MELPA. Please let me know if you have any feedback.

[alphapapa]

I think it may be possible to support this without implementing plain-language parsing. For example, the example added in e3e32eb shows a simple function that returns the timestamps at the beginning and end of the week containing a given timestamp. It would be easy to have similar functions for week-start, year-end, etc, and compose those into "last year," "last week," etc. Year start/end would be very easy with ts-apply, since the dates and times are always the same. Something like:

(defun ts-year-span (ts)
  (let* ((beg (ts-apply :month 1 :day 1 :hour 0 :minute 0 :second 0 ts))
         (end (ts-apply :month 12 :day 31 :hour 23 :minute 59 :second 59 ts)))
    (cons beg end)))

(-let (((beg . end) (ts-year-span (ts-now))))
  (cons (ts-format beg)
        (ts-format end)))
;;=> ("2019-01-01 00:00:00 -0600" . "2019-12-31 23:59:59 -0600")