HSB is a free (!!!) weekend music festival in Golden Gate Park on Fri-Sun Oct 4-6. Not 100% sure on times. The lineup can be found on their website (http://www.hardlystrictlybluegrass.com/2013/) and the schedule will be posted closer to the festival date.
I work on Friday, but am hoping to get off around 3-4 and head out for the evening, and then spend the rest of the weekend at the park. Music ends at 7pm all three nights. HSB has a really cool story; its founder has passed on a significant fund to keep the festival running without corporate sponsorship. As such, it's totally free AND operates under normal park rules (e.g. you can bring in your own food and alcohol). So basically it's one big giant picnic with a few thousand of your closest friends, and some great music. Even if you're not into folk/bluegrass, it will be a great time.
As it gets closer to the date, I can update plans. We can work to meet up at GG park or head over there together, depending on who is going and where we're all coming from. Either way, I wanted to let you girls know that it's going on and see if anyone would be interested in going out there together! Spouses, significant others, and friends are more than welcome, too.