For anyone else having this problem, you can patch it by adding and (player.surface.planet) before then on line 17 of whatTimeIsIt.lua.
It'll falsely show "SPACE!" as the location for any non-planet surface, but at least it won't crash.
there is a fork of this mod which i have been using and i presume it does a variant of that fix because i didnt want to edit the file my self, especially in multiplayer games when i would have to otherwise tell everyone to replace the mod with my version of it in order to play. where as simply switching it out with a different mod including the bugfix is much easier.