Are these people obliged to fast? Are they obliged to make up the fast?

Is it permissible for him to break his fast because his work is difficult?

He was fasting then he traveled to another country where they started fasting later; should he fast thirty-one days?

She did not make up the Ramadaan fasts that she owed for nine years

Fidyah for Missed Fasts Due to Pregnancy and Breastfeeding

If a person owes days from Ramadaan and cannot remember how many they are