I haven't really noticed a pattern.
Baby tends to be active around mid morning (10ish) especially on days when I don't wake up til around 9-10am lol (If I'm not going out I have a bad habit of lying in bed for a while, it's usually during this time that baby starts jumping).
Also, if I stay up really late, baby gets active after 11pm and well into the night like 3/4am if I'm awake I'm aware baby is active at that time. I'm guessing on nights I go to bed at a sensible time they still wake up and get wriggling at that time I'm just not aware of it.
During the day it really varies though, at random times during the afternoon or evening they will have a wriggle or kick etc but it varies what time and sometimes they will be jumping about every few minutes for ages, other times I only feel one or two movements then nothing for an hour or two, then it'll do it again.
I installed a count the kicks type app on my phone just over a week ago after the baby had a couple of "quiet" days, but the movements are so random atm I've only recorded them about twice. Other times I'm preoccupied or in the middle of doing something (watching tv or playing a game with the kids) so I don't bother getting my phone out and logging it.
I think though it had just changed position so it was facing inwards and movement was being cushioned as in the last 5 days it's been pretty active again.