1700 GMT is 1800 CET time. Central European Time (CET) is usually one hour ahead of Greenwich Mean Time (GMT).
When it's 02:00 PST, it is 10:00 CET. There is an 8-hour time difference between PST and CET.
10 AM EST is 4 PM Central European Time (CET). There is a 6-hour time difference between Eastern Standard Time (EST) and Central European Time (CET).
9 AM Central European Time (CET) = 9 AM Irish Summer Time (IST) = 10 AM Israel Standard Time (IST) = 1:30 PM India Standard Time (IST)
CET is Central European Time, which is just east of Greenwich Time (Universal Coordinated Time), so it is one hour later in the CET Zone than in London. By MT I presume you mean Mountain Time, not the state of Montana, most of which is in the Mountain Time Zone anyway, which is 2 zones west of Eastern Time. Eastern Time is 5 zones west of Greenwich, so MT is 8 time zones west of CET. So when it is 10 am CET it is 8 hours earlier in the MT zone, or 2 am. That is assuming both zones are on standard time and not Daylight Savings Time or Summer Time, etc.
There are two different time zones abbreviated EST. 1 PM CET = 7 AM EST in North America and 10 PM EST in Australia.
When it's 10:30 pm in Central European Time (CET), it is 3:00 am the next day in Indian Standard Time (IST). India is 4.5 hours ahead of CET.
8.00 EST is 14.00 CET. Central European Time (CET) is 6 hours ahead of Eastern Standard Time (EST).
South Africa is GMT + 2 CET is +1 So South Africa is one hour ahead of CET time.
When it is noon in Central European Time (CET), it would be 6 AM Eastern Standard Time (EST). EST is 6 hours behind CET.
9.00 am CET = 8.00 am GMT
9 AM CET is 3 AM EST.