Shabbat

Question

The community ends Shabbat later than 45 minutes after sunset (about 52 minutes). This is not done as a matter of convenience, but is simply the "shitah" of the community. About 15 years ago, for reasons that are unclear, they extended the time of Shabbat. I just moved in. Must I also follow the community in this case, or if I am at home, can I end earlier?