So for the longest time I had my Google Calendar set up here and tried my best to stick to it. But honestly, I suppose just because of the kind of person I am and the kind of life I lead, I just couldn't stick to it. So I'll just say this... Ah hem:
I play piano in Washington Sq Park most Saturdays and Sundays from about 1100 am to 700 or 800 pm depending on the weather and the Season. But you know, sometimes my hands need a break or I simply decide to do something else with my weekend. So I may not be there. On the other hand, sometimes towards the end of the month with impending Rent on my mind, I may go out on a weekday as well as the weekend, also 1100 am to 700 or 800 pm depending on the season.
So keeping this in mind, generally I post on my Facebook whether or not I'll be out. If you've gotten one of my cards, you can send a text asking whether or not I'm there. I'm sorry I'm not more reliable than this. Imagine how it must have been for my parents.
I hope that helps a little.