As Twenty20 indicated, you'll need to check your contract details (or, probably far easier, ask your boss). Different councils have different policies, which might vary across differing types of employment. (For example, when I worked for Sheffield City Council, we were always paid in the middle of the working month. i.e. we were actually getting paid about 2 weeks before we'd finished doing that month's work. However, that was in teaching. Other council employees will probably have had different pay arrangements).
Chris