Convert EDT timezone to GMT timezone

I am confused with several different timezones in the world. Planning to attend an online seminar but the date/time is stated in EDT, how do I convert into GMT+8, which is my country timezone?

I usually refer to the timezone conversion table at Eastern Time to GMT

For example let say the online seminar is happening at EDT 21:00, it will be 01:00, +8 which is 09:00 (the next day) in my country.