Something no one has mentioned is that there are restrictions on out of country travel. The first 6 months (training and first 3 months at site) and the last 3 months (some exceptions for education programs) volunteers are generally not allowed to travel out of the country. There are probably emergency exceptions for this, but I'm not sure a wedding would qualify as such. As others have stated, it's a matter of leave days. You accrue these at 2 days/month of service (training not included). For the first year, you can only use leave days after you've earned them. In the second year you can "borrow" against future leave days. The number of leave days you can use at once is at the discretion of the country director. I found that periods of 2.5 weeks or less were acceptable, but this varies country by country. Many people I knew went home to be in weddings, though I also know others who missed weddings and stayed in country their whole service.