Tbilisi is in Georgia and is currently on UTC+4. Its time zone is Asia/Tbilisi.
Tbilisi does not observe daylight saving time. It stays on UTC+4 all year, so the difference to any other place that also holds a fixed offset never changes.
The weekend in Tbilisi falls on Saturday and Sunday. A working day of 9:00 AM to 6:00 PM is the assumption used on the board.