Want feedback re hosting: changing the time for voting

In my challenges, I have a firm rule:  You have to vote on all other entries...it's a requirement just as important as the other rules.  And, each week, I have to DQ a number of entries that don't bother to vote.  OK, no problem so far.  But it's a disappointment when top finishers get DQ'd, since those top spots could have gone to entrants who took the time to follow the rule re voting.

This post is not to re-litigate my decision to require voting...so far, the benefits to doing this have far outweighed the possible drawbacks.  I write this to ask for feedback about a different idea.

What I will now do (assuming I decide to implement this new rule).

1.  Add to my challenge rules:  "You now have only 6 days to vote.  All entrants must vote by Tuesday." (my challenges end Wed afternoons--California time)

2.  I will also send a PM to each entrant--each challenge--reminding them (a) that voting is a requirement and (b) that they have only until Tuesday to vote, in spite of what the default notice says on the challenge site.

So, why will I do this?  So that on Wed mornings, I can zip through the entries, and DQ the ones where the entrants did not vote.  Then, those non-voters will not take up any of the top spaces...giving other entrants the glory and fame that a top finish gives. 

My initial take is:  6 days is plenty of time to vote, and given the PM I'll be sending, there will not be anyone who is taken by surprise.

But I will hold off on doing this for a few days, to give the DP community a chance to sound off.  What are the arguments against doing this?  When you post (if you do), can you also write down if you are (1) a host here, (2) a regular challenge participant, (3) a voter but not a regular challenge entrant, or (4) just a fan of the DP site (i.e., not a regular voter or a regular entrant).

Thanks in advance for your help.  And any other suggestions re to hosting will also be considered.

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http://www.pbase.com/santamonica
http://www.strataphotography.com