i have had a part time job at a bakery for a year and roughly 3 months now. i booked the last weekend of august (2016) off of work in september last year and he said he would work it out so i could have this weekend off. i double checked before booking the tickets in December and he said i could definitely have this time off before writing in the staff calendar in January that i have booked that weekend off so nobody else does. 2 other employers started at our work after this and asked for this weekend off and he is now saying that only one out of us 3 can have it off.
is this right given i gave nearly a years notice whilst one gave roughly a month and the other a few month?