I'm looking to map a dependency between 2 date fields - Closing date and Start date.

So, if a Potential is closed on e.g. 31st January, I'd like to ensure that the only available Start date could be no earlier than 1st February. 

I know dependencies can be mapped between pick list items as a standard functionality, but it doesn't look like it can be done for date fields. Has anyone got a workaround?

Many thanks,

Chris