A freind who used to work for an Eastern European airline used to tell me that they regularly rang him on his days off to do duties on the same day! Luckily, in the UK (and I understand in all other European countries) once your days off are published this cannot be changes, and if due to disruption you work into your day off the airline must give you that day off back. That said, although published days off and leave cannot be changed, but, at my (low-cost) airline at least, any changes during your days on are permitted, within flight time limiltations.
Also, you must be told of any changes for your next duty at the end of your duty, so you cannot finish a duty not knowing when your next one is and what it is. The next duty can only be changed when you actually report for it,then you can be given a different one, but since you have already reported, flight time limitations will apply.
I can imagine your partner's airline's operations must be completely chaotic! Can't be a good work-life balance for her either, never knowing when she has to report next! This whole situation sounds very odd to me.
Can you tell us Andru, is there such a thing as flight time limitations in Russia? I would be interested to know how long duties you can do, how much is minimum rest between duties, hoiw many days you can work continuously, how many days off a month you must be given, etc.
B