Thank, @bmarkus, however I'm actually after a CLI tool to manually set the time rather than a daemon. I'm trying to port our java application to RaPi2 with piCore, and it manages the timekeeping by itself. On Ubuntu it used to work with ntpdate. If there's no other option, I will try to work with ntpd, of course.
By the way, I mentioned compiling - is there a compiletc.tcz for piCore to quickly set up the environment?