Number of seconds until the next Monday?

Hi guys.

I'm writing an expiring cache object and I want it to expire on the next Monday at 12:00:01.  I'm having a really hard time finding out how I can compute that time in number of milliseconds from now until the next Monday. It doesn't have to be precise, as long as the variance doesn't creep into hours.

Anyone have some experience computing this kind of thing?  Any help is greatly appreciated! 
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