what it does
stop asking “wait, is that 3pm their time?” again.
four jobs. all in your terminal. no api call, no internet round-trip — just a plain tool that does what it says.
compare cities
$ tzdiff NYC LON TYO
NYC 09:00
LON 14:00
TYO 22:00
LON 14:00
TYO 22:00
natural language
$ tzdiff "monday 9am NYC"
your local: mon 16:00
tokyo: tue 06:00
tokyo: tue 06:00
overlap window
$ tzdiff NYC TYO --working-hours
no overlap during normal hours
nearest: NYC 19-22 = TYO 08-11
nearest: NYC 19-22 = TYO 08-11
full day
$ tzdiff NYC LON --day
00:00 NYC = 05:00 LON
06:00 NYC = 11:00 LON
...(every hour)
06:00 NYC = 11:00 LON
...(every hour)
install
three ways. all painless.
npm
$ npm i -g @v0idd0/tzdiff
node 14+ on linux / macos / windows. updates with npm update -g.
github releases
$ curl -L github.com/voidd0/tzdiff/releases/latest
single static binary. zero runtime needed. all releases →
git clone
$ git clone github.com/voidd0/tzdiff
read the source, send a pr, fork it. mit licence, no cla. repo →
why we built it
scheduling a call across 3 timezones shouldn’t require opening time.is. tzdiff prints the table in 0.04s — and it’s dst-aware, so it doesn’t lie when clocks change.
no telemetry. no signup. no api round-trip — uses the iana tz database vendored in the binary. mit forever, even if vøiddo dies tomorrow.