Depending on the period you’ll be in Germany, there are actually quite a few events happening over the year.
There’s Berlin International Film Festival in February, the second largest film festival after Cannes. You wouldn’t want to miss the 40-day event, Karneval as well. It happens before Ash Wednesday on 1 March, 2017 when Lent begins, and costume balls and parades happen across the country. There’s also the ever famous Oktoberfest, a 15 day celebration of Bavarian beer from 16 Sept to 3 Oct. Lastly, there are Christmas markets otherwise known as Weihnachtsmarkts during December, where you can visit stands selling handicrafts, wooden toys and ceramics, sample the hot mulled wine (glühwein) and hot chestnuts or just absorb the merry atmosphere.