Calculate future date to nearest Monday

Hello everyone. I am brand new to the forum and I think my issue is a doozy. I have tried searching, but have not found this particular issue addressed.

I am trying to build an Excel Spreadsheet that will calculate the return date of backup tapes from offsite storage. We have three classifications of tapes: Weekly, Monthly and Yearly. Weekly tapes are offsite for one month, Monthly tapes are offsite for one year and Yearly tapes are offsite for seven years. Tapes are picked up and delivered on Mondays (unless Monday is a holiday).

If I enter an offsite date of a weekly tape as 10/14/2013, I need a formula that would add one month and then "round" it to the nearest Monday date.

If I enter an offsite date of a Monthly tape as 9/30/2013, I need a formula that would add one year and then "round" to the first Monday of the resulting month.

I believe if I can get these two formulas nailed down, I can work out the rest. Any thoughts or suggestions would be greatly appreciated.