I've done no shortage of DIY stuff (no, I can't afford builders, either) but would never consider using something as shrieking as a circular saw outdoors before, say, 10am on a Saturday if I could possibly avoid it. 9.30 at a push. Ideally 11 on a Sunday. Sure, sometimes there are times when you just have to because the job is too big or too urgent, but I can't remember any examples.