Fetch records from sql on basis of datetime.

Question

Hello,
I am attempting to do a query with the following:
I have a table called callstats, it has 2 columns I'm interested in: OfferTime & AnswerTime.  The data contained in them is in the format  dd/mm/yyyy hh:mm:ss 
Offertime always has a data in it, but sometimes AnswerTime can be empty.
The table itself has a year's worth of data.
I want a query that will give me whatever month's worth I query, I've tried several variations of the following to get a month's worth and nothing
"SELECT OfferTime, AnswerTime FROM callstats WHERE OfferTime LIKE '%Jan%' AND AnswerTime LIKE '%'"
This isn't returning any results.  Basically I'm interested in entries for both columns, I want it to check the first column, if it's Jan, then read it and the 2nd column regardless if it's got data in it or not.
 
Thanks in advance.