There is a statutory minimum for the amount of annual leave that a team member is entitled to. In the UK, this minimum is 5.6 weeks.
This works out as 28 days for a full time, 5-days-a-week team member: 5 x 5.6 = 28 (Note: this can include bank holidays and national holidays).
A part time employee is entitled to the same amount of holiday pro rata. For example, if a team member works 4 days per week this would amount to 23 days’ allowance (4 x 5.6 = 22.4). Legally these holiday allowances must be rounded up (not down) to the nearest day.