Tier 4 Proof of funds question

Dear friends,

I have a question regarding the proof of funds section of the application, namely the bank statements. The guidance states the following.

You must show that you have held the required money for a consecutive 28 day period (finishing on the date of the closing balance) ending no more than 31 days before your application.

I am confused about the 31 day part. Does it mean that I can use a bank statement, the closing date of which is within the 31 day period of application date, or does the start date of the statement has to fit in that window?

As an example imagine if i applied for the visa today fay . Since today is the 27th of Feb, can the closing date of the bank statement be 27th of Jan (today minus 31day limit of application)? Or is this the minimum acceptable starting date of the statement?

O