The holy Muslim month of Ramadan is due to begin on the evening of Friday 28 February or Saturday 1 March, depending on the moon. Eid-al-Fitr, the celebration that marks the end of Ramadan, is expected to fall on Sunday 30 March or Monday 31 March.

During the month of Ramadan, Muslims spend a period of 30 days abstaining from food, drink - including water - and smoking during daylight hours as a means of celebrating and reflecting on their faith.

The guidance encourages employers to offer flexibility around holiday entitlement, working patterns and break periods.

In addition, Unison is reminding both workers and employers that it is within the Equality Act 2010 for all employers to ensure flexible working and provide reasonable adjustments for workers wishing to observe Ramadan, which includes fasting, prayers, charity and reflecting on the Quran.

Unison general secretary, Christina McAnea, said: ‘Employers should respect and accommodate your needs during Ramadan, whether it's through flexible hours, prayer space or the time you need for fasting.'

According to the Muslim census, if Muslims feel their workplace is supportive during Ramadan, they are twice as likely to stay at their current place of employment.