Is anyone able to provide an example of what an average working week looks like for an ATC? Enroute if possible. Is it a rotating roster between mornings, afternoon and night shifts?
Unfortunately rosters vary a lot from group to group, because they are written around traffic patterns, so there is no typical en-route roster pattern. On some rosters the shifts vary over a 6 to 18 week cycle, so there isn't even a typical "week" on a groups roster.
Having said that they are all designed with FRMS11 (fatigue "management") and POR (principals of rostering), so there are recurring themes. A shift cycle will be between 3 to 6 shifts, followed by 1 to 3 days off, the another 3 to 6 shifts (but not necessarily the same ones as last time) etc. Usually the first shifts will be mornings, each subsequent shift usually starting later. Alternatively the may be all mornings, or all afternoons etc. This is a simplification though.
Shift swaps are possible, but difficult. The swapped shift has to comply with POR and usually FRMS11, as does the shift of the other person, and of course you have to find someone willing to swap.
How much notice is required if you need a day off?
Depends on why you "need". If its a family funeral or a sick child or your house just burnt down etc then there are various provisions, (carers leave, special leave, bereavement leave etc.) so you just give as much notice as possible, sometimes its none.
If you just "want", then you are probably out of luck. You will get between 4 and 6 weeks recreation leave a year, but it need to be requested 14 months in advance, and even then you won't necessarily get it. Something to consider very strongly before going into this job. You will be working most Christmases, New Years, weekends, partners birthdays, kids sports days. club get togethers etc. On the other hand, if you are on a morning, you have most of the afternoon/evening off and vice versa, so it can work out.