Artful Dodger: there can be many reasons, some examples
- an unexptected longer illness
- an unexpected change of jobs where internet access is more limited than your previous job
- an unscheduled long vacation
- an unexpected illness of a family member
- unexpected computer / provider problems

the policy of vacation days (or even no vacation days) is different per game site

the policy of this site is to allow vacation days .. and at the moment the policy is to allow rebuying of more vacation days