Missing Reports

Hi Everyone,

I completed implementation in January, As at March I could generate report for February.

However, in April I discovered I can only generate report for March and I am unable to generate for February.

Although in my report, I created one for Business Hours and another regular report. The regular report can generate for February in April but the Business Hour can't generate the report. 

What could be the cause?

I need help, its very urgent.