British Citizenship - 270 Days rule.

I am going to apply to BC on the basis of marriage to british ctizen (3 years - 270 Days not more than 90 in the last year), This is my theoratical situation: Say I have entered the UK on a spouse visa on feb. 2003 so potentialy I would send in my application on feb. 2006 (exactly 3 years later) but what if i decide to send it in April 2006 (for example)? Should I start my day count (270) from April 2003?

Thanks for any replies!

Time line is 3 years preceeding date of application i.e. if application is in April 2006 then April 2003. You must have been physically present in the UK on the relevant date 3 years ago - such presence must have been in accordance with the immigration rules.