"At the weekend" is common in British English. "On the weekend" is preferred in American English. "In the weekend" is less common in both English varieties
Friday is a special day for relaxation and getting off work. Friday is the day when everyone is in a good mood. Friends make Fridays more special when together
Americans ask about weekend plans from Thursday to Wednesday. Response format: plan + "because". Examples: movie, travel, or birthday celebration
"At the weekend" is used in British English. "On the weekend" is used in American English. "In the weekend" is rarely used in either language
"During the weekend(s)" is more common than "at the weekend" or "at weekends". Both "at" and "on" are correct and mean the same thing. "At" is more common in British English
"At" is used in British English, "on" in American English. "The weekend" refers to specific weekend, "(the) weekends" means every weekend. Cambridge Dictionary recognizes "at weekends" but not "at the weekends"