It varies week to week and month to month, very difficult to say. Even school holidays can be hit or miss because holidays, school, childcare arrangements have different results for different people. Many punters have grown up children or just carry on with usual jobs.
Regards weekends I don't see it as any special day apart from it sometimes being a day on which events linked to my other interests happen to be held. I quite like it as a work day - I've had jobs which required working weekends right from my first part-time around school-times job. I have noticed some Sundays can be fab, others completely dead or full of people phoning part-way through a bender or come-down.
I stopped trying to predict busy/quite days long ago and mostly offer the hours/days/times/months that work for me with the odd wild card thrown in for one or two reliable, long-term regulars. If anything a day that was repeatedly quiet would flag it up to me as potential for it to become the day I take off.
I've always found over thinking and trying to manipulate things to persuade work to happen at a certain time generally only leads to a lot of unnecessary brain work. For this reason I'd say you decide on your own parameters based on what suits you, and make your own choice from the offers you received.