Set time for tracking link

Hi,

Love the tracking capabilities, works excellent.

At this time I can give people a 24 hour link or a non-expire link.

Could it be possible to just set the amount of hours of the link? 

I do a lot of Audax / BRM rides which can take up to 90 hours. Please make the amount variable so when giving the link I can set it for whichever length I want. e.g. 48 or 90 hours.