The invention discloses a method for concurrently handling registrations before and after attendance checking events in attendance checking calculation. Influence on attendance checking calculation from time of attendance checking event registration is eliminated. The method includes firstly storing registration time of the attendance checking events when recording attendance checking events such as fill check, absence and work overtime, setting before-event registration if the registration time is earlier than the attendance checking date of the attendance checking events and after-event registration if the registration time is later than the attendance checking date of the attendance checking events; automatically running an attendance checking calculator at fixed time every day and calculating normal attendance checking events and postponed attendance checking events in a former turn. By means of the registration time of the attendance checking events and the automatic operation mechanism of the attendance checking calculator at fixed time every day, the attendance checking events before and after registration can be concurrently handled, and logical processes of attendance calculation is free of influence from the registration time of the attendance checking events.