When Does the 30 Day Notice Countdown Start

[Andrew Jacoby]

Hi.  I have a tenant who is currently on a month-to-month rental agreement. 

I know that in Tennesee, I must provide a 30-day notice to vacate (no violations in this scenario).  When does that 30-day countdown start?  Is it the day the notice is given?  For Example: 

If I give the notice on February 15th.  Does that mean the lease ends 30 days after on March 15th, or would it be at the end of that month on March 31st?  Any help pointing me in the direction of the proper codes that I can look up as evidence would be very valuable as well. 

Thanks in advance!