Date and Time problem

I have a problem regarding the time and date. I am from India and so the time is 5 h 30 m more than that of Greenwich. When I change my location from India to Greenwich so time should be reduced by 5:30 minutes automatically, but it doesn't happen. One of the reason of it maybe as it takes system time and it doesn't reduce time as if I were in Greenwich at the time specified by my system and the view of stars is for that situation. If this is the condition I don't think the "hour angle" of the stars should be reduce by 5 h 30 minutes. but in the program it is happening without changing the time of the software.

Another possibility is it is showing view of the stars from Greenwich but time and date is measured in Greenwich from the reading of an Indian Clock. But how does the software know that it is India even though place has been selected as Greenwich?

By the way, I have observed stars,Jupiter, Saturn etc correctly using this software without any correction in the time . That means it at least shows time correctly in India.

Please help me to understand the fact and where I am making mistakes.