Currently working it
Honestly, it heavily depends on the actual day/week itself as well as what yard you're working. Today for example the "Shed" was extremely busy whereas both the "Downs" and the "Ups" only saw trains in and didn't need to do any shunt work. Tomorrow, it could be completely different.
Generally, the shifts tend to go something along the lines of:
Weekday Earlies - Turn up, finish seeing the trains out of the yards usually from 5:45 until around 6 or 7 depending on the yard, come back and get an arrival sheet and then be back in whatever yard for the first train which varies from around 8 to 9 depending on the yard. The shed tends to be the busiest as it has all the rush hour stock that came up from Dover/Ramsgate/Ashford (Almost entirely 375s) coming in one after another, these tend to need either splitting up depending on what unit needs to finish where as well as Tanking (Water refill) and CET (toilets emptied), both the Tanking and CETs are done by the cleaning staff, we're just required to move the units as needed. That being said, some days all the units will come in, sit there, and go back out without us even touching them.
The UPs and Downs are very day-to-day dependent as they'll take all the "Metro" stock (networkers / 376s) which normally end up going out the same way they came in but, networkers especially, sometimes require re-forming.
Weekday Lates - Tend to be the "easiest", you come in, see out the afternoon rush hour departures, come back and wait until they start arriving back in the evening and go home whilst they're still coming back. There's not usually a great deal of shunt work as most units are back out working; this shift is the one that does most of the "yard-to-yard" work (I.e. Moving a train from the Downs to the Shed or Ups to the Downs etc) so they're all in place for the night shift. Due to this, if they need cover on the early or night shifts, this team will be the one that's asked first or be given a shift swap if no one offers, however, I've never yet seen anyone have a forced shift change, someone always agrees to change over.
Weekday Nights - The busiest by far, once you come in you'll be seeing in the remainder of the trains and then forming them for the next day's service, Friday is typically the worst as there's a lot of variation (pretty much getting rid of every 2 car networker) between a Friday run and a weekend run. Usually a few CETs as well as carrying out all the train preps for the next day as required, the load is split between us and a prep driver but if anything goes wrong, this is the shift that'll deal with it. Say a PA system isn't working, you'll need to re-form that train to "box in" the cab that isn't working properly on top of everything else. There are also some yard-to-yard shunts as required if units come in the wrong places. You'll then start seeing trains back out from 4 am onwards.
Weekend Earlies - Saturday - Honestly, it's a sleeper shift. Everything is sent out by the Friday Night turn and there's 99% of the time, never anything else to go out. You'll have a few shunts to do roughly mid-morning to set up for the Sunday service but as everything has already gone there isn't that much to do. This shift will get the vast majority of stock and engineering moves as Slade Green will send a unit to us that's just had an exam and take another one away, this doesn't involve much for us apart from giving a slot and taking numbers
Sunday - Same as above although there is more shunting during the day as we'll have more units left over.
Weekend Nights - Not that different from a Weekday Night apart from you coming in earlier.
With Weekends, either Early or Night, if there are any Engineering blocks that require the depot to be isolated, we're kept on hand as required but this usually ends up in you coming into work, sitting there for 12 hours and then going home again without once going into a yard.
Across all shifts, there are normally plenty of downtimes for us to take our breaks without needing to worry about it too much, some days we'll take them at different times than usual but I've never had a day where I've had to stop and say "I need to take my break". Once you are out in a yard however you are working flat out until you come back so time does pass quickly