Since there's one person in charge of each contest, there's bound to be issues with contest dates and such. People get busy at times and don't have the ability to maintain contests with precise timings. This isn't the only contest that doesn't have proper schedualing either (in terms of making voting threads/announcing winners/etc.)
Personally, I just thought of a good idea. All contest submissions should be run and maintained by all moderators. Then when people make submissions for contests, they PM all submissions to the NB bot (because all mods have access to that account). This way, there's always a mod on to maintain proper contest times and everything would run more fluently instead of a weekly contest really turning into a monthly contest or etc.
Make it in a format somewhat like {Contest} - {Contest #} - {Username} when PMing NB bot to keep submissions organized.
Actually, I'm going to make a full thread for this.