As a volunteer, you typically have to put in an effort of 32 hours spread over the entire festival period or 24 hours during the last four days of music, which run from Wednesday 28 June to Saturday 1 July, when all stages are open.
On some teams, it is possible to get a senior role, which is an offer for volunteers aged 65+, where, if necessary, you can just put in 75 percent of the hours you would otherwise have to. If it is not clear from the volunteer posting whether the team offers a senior role, you can ask the contact person.
On some teams it is also possible to volunteer for a single day by putting in an effort of eight hours and gaining access to the festival on that day. The number of hours can be seen from the various volunteer postings about available roles as a volunteer.