Aqiqah is sunnah and mustahab on the seventh day. If it could not be done on the seventh day, then on 14th day, and if not then on 21st day and if not then it can be done any time. However it is better to perform it on seventh day i.e. if born on Friday, it should be done on Thursday.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband