@Bernardo165
theoretically it should be more or less immediately but I have noticed delays of 10 - 15 mins, which could be critical for popular dates.
Worse still, sometimes the synch just DOESN"T synch.
I simply don't trust technology. I have all the apps on my phone, so when a booking comes through - I manually block on the other sites. When the synch kicks in, no harm done ( blocked twice). MUCH more desirable than getting a double booking and needing to cancel one with the associated penalties.