Undertime - pick a meeting time

This program allows you to quickly pick a meeting time across multiple timezones for conference calls or other coordinated events. It shows all times of a given day for all the timezones selected, in a table that aligns the time so a line shows simultaneous times across all timezones. This takes into account daylight savings and other peculiarities (provided that the local timezone database is up to date) so you can also schedule meetings in the future as well.

Usage

Timezones should be passed on the commandline and are matched against the list of known timezones, as defined by the pytz package. Exact matches are attempted at first, but if that fails, substring matches are allowed, which makes it possible to do this:

undertime.py New_York Los_Angeles

The complete list of timezones is also shown when the --print-zones commandline option is provided.

Colors are used to highlight the "work hours" where possible meeting times could overlap. You can change those work hours with the --start and --end flags. Because daylight savings may actually change time, you can also use the --date time to pick an arbitrary time for the meeting, using natural language (as parsed by the parsedatetime library). The current time is also shown, in bold.

Full usage is available with the --help flag and the manpage. Instructions for how to contribute to the project are in CONTRIBUTING.rst and there is a CODE_OF_CONDUCT.rst.

Known issues and limitations

There are weird alignment issues when using colors, which seems to be a bug with the upstream terminaltables library, filed as issue #55.

It is possible that daylight saving times computations are incorrect. There are no unit tests for this program, which was only manually tested with some commonly used timezones.

Timezones are a delicate and complicated subject, and change constantly. What may be applicable to your location at the current time may not be reflected by your operating system or the chain of software used by this program to determine time.

It should be possible for the program to show the user which are the best times to possibly do a meeting. Those, for example, could be outlined in green or underlined to make it more obvious when the best matches are. Another suggestion that was proposed is to restrict the display to overlapping timezones (issue #3).

There is no --version flag because of limitations in Python's performance, see issue #4 for a full discussion.

Undertime was written using Python 3.5 and there is no garantee it will work in older Python releases.

Credits

This program was written by Antoine Beaupré and is licensed under the AGPLv3+. It was inspired by the overtime-cli program and the timeanddate.com site. Another similar tool is worldchatclock.com and its beautiful round interface. I also found out about tzdiff a few months after writing undertime.

I rewrote overtime-cli in Python because I felt we shouldn't need a Javascript virtual machine to pick a time. I was also curious to see how such a rewrite would look like and was tired of loading a web browser every time I needed to figure out what time it was elsewhere in the world or when I needed to coordinate international meetings.