Notice of termination of employment

My present contract show who if notice is given by the Employee-1 week,irrespective of lengh of service.
So if my present work 4 on,4 off.If decide leaving than i need give simply 7 calendar day notice or 4 my working day???Thank Don t want ask at HR or another driver because why need all this" ■■■■■■■■".May be i leave after 1 week or just after 5 years or more.

Unless the contract says otherwise I would say it’s a calendar week not a working week.

Give ACAS a ring for any employment law’s