pdd - Tiny date, time difference calculator with timers.

       Arun Prakash Jana <engineerarun@gmail.com>

pdd  (python3 date diff) is a small utility to calculate date and time difference. It can also be used as
       a timer. If no program arguments are specified it shows the current date, time and timezone.

       Features

       - easy to use, minimal dependencies
       - calculate date and time difference
       - add, subtract duration (timeslice) to/from date (time)
       - calculate diff from today and now
       - countdown timer with command piggybacking
       - custom resolution stopwatch
       - non-verbose mode for background timers
       - show current date, time and timezone
       - follows ISO 8601

       Operationalnotes

       - ISO 8601 format. Month can be specified as month number (e.g. Jan - 1, Dec - 12).
       - Time is in 24-hr format.
       - The absolute difference is shown. Argument order is ignored.
       - The end date is excluded in date difference calculations.
       - Hour, minute or second can be omitted. Partial inputs are recognized as mm:ss or ss.
       - The keybind to stop timers is Ctrl-C.

       1.  Calculate diff from today:

              $pdd2014Jan15

       2.  Calculate diff from now:

              $pdd24:00:00$pdd0

       3.  Calculate date diff:

              $pdd-d1983jul32014115

       4.  Calculate time diff:

              $pdd-t45:506:17:33

       5.  Show current date, time and timezone:

              $pdd

       6.  Specify time with roll-over:

              $pdd-t5:80:756:17:33

       7.  Add a duration (3 years, 2 months, 1 day) to 28 Feb, 2000:

              $pdd-d2000FEB28321--add

       8.  Add a timeslice (1 hour 2 mins 3 secs) to 23:45:37:

              $pdd-t23:45:371:2:3--add

       9.  Add a duration (3 years, 2 months, 1 day) to today:

              $pdd321--add

       10. Add a timeslice (1 hour 2 minutes 3 seconds) to now:

              $pdd1:2:3--add

       11. Subtract a duration (1 day) from 1 Mar, 2000:

              $pdd-d2000Mar01001--sub

       12. Subtract a timeslice (1 sec) from midnight:

              $pdd-t00:00:000:0:1--sub

       13. Subtract a duration (3 years, 2 months, 1 day) from today:

              $pdd321--sub

       14. Subtract a timeslice (1 hour 2 minutes 3 seconds) from now:

              $pdd1:2:3--sub

       15. Show the day of the week on 15 Jan 2014:

              $pdd--day2014Jan15

       16. Start a countdown timer or stopwatch in quietmode in the background:

              $pdd-qs&$pdd-qc3:0:0&

           To see the final counter run fg and press Ctrl-C.

       17. Run a command when countdown timer reaches 0:

              $pdd-c00:00:5-r'ps-aux'$pdd-c00:00:5-r'notify-sendpddexpired'

https://github.com/jarun/pdd

       Copyright © 2017 Arun Prakash Jana <engineerarun@gmail.com>

       License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
       This  is  free  software: you are free to change and redistribute it. There is NO WARRANTY, to the extent
       permitted by law.

Version 1.7                                        03 Dec 2022                                            PDD(1)

       pdd - Tiny date, time difference calculator with timers.

-h,--help
              Show help text and exit.

       -d,--dateyyyymmmdd[yyyymmmdd|ymd]
              Calculate date difference.

       -t,--timehh:mm:ss[hh:mm:ss|h:m:s]
              Calculate time difference.

       --add  Add a duration or timeslice to date (/today) or time (/now).

       --sub  Subtract a duration or timeslice from date (/today) or time (/now).

       --dayyyyymmmdd
              Show the day of the week on a date.

       -c,--timerhh:mm:ss
              Set a countdown timer with duration in hours, minutes and seconds.

       -r,--runcommand
              Run command when countdown timer reaches 0.

       -s,--stopwatch[resolution]
              Start a custom resolution stopwatch. resolution can range from 1 to 9. Default 3 for millisecond.

       -q,--quiet
              Quiet mode for a countdown timer or stopwatch to be run in the background. The  counter  is  shown
              only when Ctrl-C is pressed.

https://github.com/jarun/pdd/issues

pdd[OPTIONS][KEYWORDS...]