Thank you Hurdity!
I should maybe have said 'zero hours contract shift'.
You know that type of job where you're not guaranteed any set hours per week or month? You may get one three hour shift in a month, or you maybe get a ton of shifts one week (that maybe amounts to 40+ hours) and then nothing at all for the next three weeks? All just depending on how much staff cover they need. It's one of those kinds of contracts.
Actually, I have two of them that I juggle.
I really like the freedom they give me, so I can do my own work. So if I get offered temporary contract for my own work, I can just tell my zero hours jobs that I'm not available for that week/fortnight/month. Go and do my temporary contract and then make myself available for shifts again.
The downside on those sorts of contracts is that you have very little in the way of employment rights. So if you're scheduled for a shift and can't make it because you're ill, you don't get paid. Well, I have one zero hours job like that, and my in my other zero hours job where you get a little more, in terms of sick pay, holiday pay, cancelled shifts payments (like if they cancel a shift and you lose the work/money because of it).
So, yeah, it's really, really essential that I do the work and am not stopped by the heavy periods etc, because otherwise I get nothing, no income.