I've worked all weekend unpaid. Can I take a day off in return?

Many companies operate a scheme whereby workers can take Time Off In Lieu (often abbreviated to TOIL). This means that employees can claim back extra time that they have worked, by taking equivalent time off, normally within a set period after the additional work.

If your employer operates such a scheme, you will be able to find details of it in your staff handbook. There is no statutory right to TOIL, so if you don’t have a scheme, or you’re not happy with the scheme, you should consider joining together with your colleagues (preferably via a union) and negotiating with your employer.

Also, even where your employer does not operate a formal TOIL scheme, it might be worth approaching your manager anyway about the extra work you have been doing. He or she they may still be able to offer you time off at his or her own discretion to compensate you for the extra work you have been doing unpaid. Don't wait too long to request this though. The older the extra work, the easier it will be for the organisation to decline.

It may be the case though that your contract or staff handbook includes a clause which permits your employer to expect you to work extra days without being able to claim anything back. This might say something along the lines of  "May occasionally be required to work weekends". Flexible working is a priority for trade unions, so if there's a union at your workplace, they are more likely to have negotiated a TOIL-type agreement, or appropriate pay or overtime to compensate for this.