Using Lua to format 0 seconds as 00:00:00
duration, lua, time
Solution
In most systems (ie, POSIX), `os.date("%X",0)` gives you the time of the epoch, which is 00:00:00 (Coordinated Universal Time, UTC), 1 January 1970. You get `20:00:00` because you're in a different time zone.
To force UTC instead of your time zone, start the format with `!`. This is mentioned in the manual.
So, use `os.date("!%X",0)` to get `00:00:00` as desired. It'll work with any number of seconds less than a day (86400). For instance, `os.date("!%X",70)` gives `00:01:10`: 1 minute and 10 seconds.
Problem
I'm trying to format a duration (in seconds) as a time and I'm getting results indicating that I'm supposed to account for an epoch somewhere. I expected `os.date("%X", 0)` to produce "00:00:00" but it is returning "20:00:00" as well as a date value of "12/31/69" (I don't need a calendar date though). Is there a standard way of getting a time duration string that causes 0 seconds to produce a clock representing a total of zero seconds? I can't seem to find an example anywhere of what I'm trying to do. Thanks