… days, weeks, etc. hence
Definition 1 of 1
Pro Tip 1/3Future Events
Use this phrase when referring to specific events or outcomes that are expected to happen in the future. 
The new policy will take effect ten days hence.
Pro Tip 2/3Time Expression
It expresses the time from the present moment, not from any other point in time. 
We will reconvene three weeks hence to evaluate progress.
Pro Tip 3/3Slightly Formal
It's more formal than simply saying 'in two weeks'. Its use often adds solemnity or formality to the statement. 
The ceremony will be held a fortnight hence.