The time difference is 6 in winter and 5 in summer compared to GMT.
Moreover, it should not get surprise you that during your flight, to 15h/ 16h (GMT time), the air hostess kindly ask you to full the shade of the window while it is daylight. It is 21h/ 22h Vietnam and it is night .... and we must try to sleep during the flight.
Vietnam is in the GMT + 7, so to know the time difference between your country and Vietnam, it is necessary to know the GMT of your country: for example, your country is in the GMT + 3 and you shift 3:00
Even if it is not obvious, it must, upon arrival, try tracing your meal times and sleep on those from Vietnam.
In Vietnam, we usually get up early (between 5 and 6 o'clock in the country, 6 and 7 o'clock in the city) because of the sunrise. Getting up early is enjoy the day.
What happiness!! You'll find that you will not be alone!!
Most banks, utilities and administrative offices are open from 7:00am to 11am and from 13:00 to 17:00. Tourist stores are open every day of the week non-stop. The markets open early and often working until the end of the afternoon.