As described above, consecutive sessions are merged first
Prices for each individual session are calculated as follows:
Start and length of a session are in general the actual used time. If it's a cancelled session, it is the booked time
Calculate the number of minutes which are during the night
Calculate the number of minutes which remain at night starting 6 hours after the session start: This is the time period which will obtain a rebate for long-term imaging.
Calculate the number of minutes during the day
If a session is cancelled less than 24h before session start, 75% of the normal price are billed.
For all groups contributing a system (see below), if the sessions' system is not their own instrument, the price is reduced to 50% (if it's their own system, they don't need to pay anything).