I hoped someone would complain :-)
What the client want's to type has nothing to do with what you put into the database.
If the client want's to type 'March 2000' you make a function that accepts 'march 2000' and makes a timestamp out of it. Strtotime() is pretty good at that.
Once you have the timestamp in the database you can use PHP's date() function to get back to 'March 2000'
Point is: if you start literally putting 'March 2000' into the database, you are basically f*cking yourself up the bottom with a large aubergine. That string is useless. You can't calculate with it, so you can't use it in any queries except those where you happen to be looking for 'March' or '2000', and then you're just making slow queries.
What's more, the string uses a lot more space in the database than the timestamp.