On most days, including weekends, these time slots are available:

Slot	CET Europe	GMT England	EST US East Coast	PST US West Coast
A	1PM	12PM	7AM	4AM
B	3PM	2PM	9AM	6AM
C	5PM	4PM	11AM	8AM
D	9PM	8PM	3PM	12PM
E	11PM	10PM	5PM	2PM
F	1AM	12AM	7PM	4PM
G	3AM	2AM	9PM	6PM

But they might be booked, so you need to get an appointment at least a couple of days in advance.

The correspondances of time is for the winter half of the year. If you want to be sure, check the World Time Server