Kind of....but you don't need to provide "proof" since the charities are like corporate partners. We have teams for each charitable organization, and you can join whetever team you want. Events are during normal work hours....some happen at our office, some happen offsite. If offsite, the company provides transportation to and from the site.
None of our full time employees are pad hourly, everyone is salaried. When you put volunteer time in it goes to your calendar, managers know not to schedule meetings/deliverables etc as they will be unavailable. And yeah, you don't use your personal or vacation time for this stuff....thats why the have a separate bucket for volunteer time.
Some events, like bike rides or walks etc, might happen on a weekend...but there definitely isnt an expectation for people to sacrifice their weekends or after-hours for this stuff.
I've been involved with a bunch but some of them very powerful and heartbreaking. To experience that with someone you work with is a very powerful thing. For example, one of the organizations is a women's shelter. The stories you hear are horrifying. We help with resume writing, mock interviews, clothing drives to wear to interviews etc....try and help a ittle to get them indpendent and on their feet again. You go through that with someone whom you may see at the office everyday but never interact with and it definitely makes a connection between you both.
And ultimately, albeit in a very indirect or roundabout way, I think it has a very positive impact on the work environment.