„pora roku” = time of year (season), „pora dnia” = time of day.
„pora” by itself will usually be assumed to be short for „pora dnia”; „o tej porze już są w pracy” = “at this time (of day) they are already at work”), „jedzą o dziwnych porach” = “they eat at strange times (of the day)”. Likewise someone might call you or come to your house „w porę” (at a good time) or „nie w porę” (at a bad time, bad timing).
„pora” could also be short for „pora roku”, but only if it’s clear from the context that you’re talking about seasons, like „kwiaty zawsze rozkwitały o tej porze” “the flowers were always blooming at this time (of year)”.
You could also say „pora tygodnia” = “time of the week” (although that’s not so common), or „pora miesiąca” = “time of the month” (although that would usually be a reference to the menstrual cycle).
You also have „od tej pory” (from this time) and „do tej pory” (until this time); in this case it’s a more general „time” (not „time of day/year…”); similar to „od tego czasu” and „do tego czasu”. Of course, „odtąd” and „dotąd” can also be used.