Mail timings in Gmail

I was having continuous trouble with different timings appearing against my mails in Gmail. Could not just bear this fault from Google. How could Google not take care of this?

But today, searched and I am back with appreciation for Google. There is a entry in Gmail help. Link is here.

What I am not able to understand is why it does not stick to the Time Zone entered against the Google Account. They have considered two things here: Timezone entered and System date and time.  This makes the timings against mails dynamic, calculated every time a mail is open on different systems. I was always under the impression that it considers only the Time Zone entered.

In the Account settings, there is an option to associate another mail id against a gmail id. This helps in integrated services of Google. Like Google Calendar invitations sent to any of the primary or associated mail ids will show in gmail id.