Why we can add time-dependent workflow actions for

           1) When a record is created, or when a record is edited and did not previously meet the rule criteria

            2) Only when a record is created

but Why we cannot add time-dependent workflow actions for Every time a record is created or edited ?

please give me explanation

Why we can add time-dependent workflow actions for

           1) When a record is created, or when a record is edited and did not previously meet the rule criteria

            2) Only when a record is created

but Why we cannot add time-dependent workflow actions for Every time a record is created or edited ?

please give me explanation