To this question everyone will answer: “ of course: Children“. I naturally also. But although this is my basic adjustment, I always push my borders, if days with double dates are occupied.
That is the case whenever school and kindergarten announce its dates so short that working parents have not at all the chance to make new arrangements.
Last Thursday for example: On Thursday child No.3 had a performance in her kindergarden and it was completely proud that it was allowed to play the moon. The invitation to this performance was distributed by the kindergarten one week before. ONE WEEK BEFORE! How should this new appointment be planned in such a short time?
I had a customer date, a flight and a rented car was booked and I could not shift the date. Thus child No.3 played the moon without mummy in the audience.
For outstanding ones the situation is now completely clear: the work was more important in this moment than the child. But everyone, which tries to synchronize work and family , knows these situations.
How to behave now?
On the one side: The customer date is booked for months and who first booked, gets the date. A firm project closing date was assured to the customer, which is to be kept. If it comes to delays, which I have to answer for, I pay the agreed upon payment of damages.
On the other side: The child is proud over his role and would like to be admired gladly. Me as a mother I promote and support my child and show mean pride over its achievement. If I do not come as a spectator to the performance, the child is disappointed and feels neglected.
Why do school and kindergarden bring me again and again into this dilemma?????
Can’t Kindergärtnerinnen and teachers introduce themselves that we do still different things, than to wait as on short term dates from school and kindergarten? Can educators not plan their dates also on a long-term basis?
In order to keep the eternal disappointments small, we introduce the rule: who first booked gets the date. That is valid both for the invitations to child birthdays or family celebrations, for guests or kindergarten dates. No more debates over ‚ I would prefer to go ….‘ and also no attempts to shift dates.  
How do you go forwards with overlappind dates? How do you explain to your children, why which date proceeds now?