Don't rely on DateTime.Now.ToString() to populate varchar database fields that are used for holding dates. Or even better still don't use varchar fields for holding dates in the database - unless you've inherited this scenario and don't want the risk/time to factor it out.
If, for example, the user inadvertantly has their browser language/culture set to say en-us instead of en-gb you'll get a date like so '03/31/2013 09:00:00 AM' instead of '31/03/2013 09:00:00'. This will then make any date processing you do on this field go SPLAT. Other developers/project manager may be mildly curious as to why you're using a varchar field to hold a date, at which time you will promptly blame someone else for it :) (He did, Ed.)
Solution, set the culture in the web.config
<globalization culture="en-gb" uiCulture="en-gb" />
There is no quick and dirty, only dirty.