Time and time only. You should get it on the given turns in the OP. Note that only the first reform was tested by Nightshift.
The reform is silent (no event notifies you it has happened) and has little effect, it is possible you have simply missed it. Check your units, as I understand it, 3 of them should have changed to "Late germanic..." as opposed to "Early", with slightly better stats. At least that's for the first reform.