Pesachim 50 - Customs
In the times of the Temple, people did not work on the day before Passover: this was a day of bringing a Passover sacrifice, and it had a character of a holiday. Later, some people adopted a custom to refrain from work on this day, while others did not. Therefore, if one is from a town where they work on this day, and he comes to a town where they don’t - he, too, should not do any work. In general, one should follow the local custom, in order to avoid disagreements. Moreover, if he comes from a town with a more stringent custom, he is bound by it too. Therefore, one receives the stringencies of the place he left and the stringencies of the place he came to.
Similarly, on the Shmita year, one has to remove from his possession the fruit he has collected, once they are finished in the fields, and leave it for everyone to use. If he comes to a place where they are already putting the fruit into the streets for everyone’s enjoyment, he too has to do it too, even if in his home town the time to remove the fruit has not come yet and vice versa.
Art: A Small Disagreement by Francesco Peluso