I have not had this issue before with Gmail, but discovered it this morning when emails sent back and forth yesterday led to a communication breakdown based on who sent what when. I, too, was getting really frustrated with this. Scroll down to Google Account settings section and you will see the link for Google account settings. If you ever need to get to your Google account settings from Gmail, click on the Settings link (upper right of screen), then select the Account tab. It's probably needs to be change to the correct timezone setting that you want.
#Mac mail gmail reply from same account Pc
If the time is still wrong, check the timezone setting of your your PC clock. The time stamps on your messages should now be correct. To go back to your Gmail mailbox, click on the Gmail link on the right. You should now see the correct timezone displayed on the Personal information screen. Once you make the change, click on the Save button at the bottom of the screen, followed by clicking on the Back link in the yellow confirmation notice.Then in the account information screen, choose your timezone by clicking on the check box next to Display all timezones followed by change the timezone (using the pull down arrow). To change it, click on the Edit link next to Personal information.