When is the limit to contribute to contribute to 401K: 12/31/2010 or another date?

I never contributed to my 401K before and I would like to start contributing.

I know the limit for 2010 is $16,500 but I would like to know when the limit is to contribute

this amount for the year 2010. Is it the end of current year 12/31/2010 or a different date such as when I have to file my income taxes (4/15/2011) ?



Thank you
12/31/2010 - contributions can only be made in the form of salary deferrals on your part.



The 4/15 deadline applies to IRAs - not 401(k) plans.