Some stations will have allocation swaps or period swaps on set days where all staff email one an another to see what blocks each can grab.
This is mostly on the larger stations ala Kings Cross for example.
Definitely not how it works at King's Cross! At the majority of stations you'll get to know your colleagues preferences, and it's generally on a one to one basis.
You'll be put into a certain annual leave allocation period and you can swap either the entire period or odd weeks with any colleague on the same group. The dates corresponding to each period are published in advance (and it's fairly easy to work out what you're doing for the next few years as you rotate through each of the periods) and most cover group administrators will also publish a list of who is in each period. It's then a case of arranging things with someone who has what you need and vice versa. It's not unknown for three- or even four-way swaps to take place to keep everyone happy.
For your first year, however, if you have any pre-arranged annual leave this will be honoured. Make sure you tell your cover group admin at the earliest opportunity, however - don't hold off and book something else and try and game the system! You'll have a meeting/induction with them after finishing Stations Core licensing.
It's unlikely you'll struggle to get the dates you want each year, it just takes a little bit of effort and forward planning. School holidays and Christmas in particular tend to be very in demand.
