Hi,
In Outlook 2007, this can't be changed. The meeting attendees can't change the time zone when they open the meeting on their calendars.
Anyway, it should display correctly on the calendar in the attendee's time zone.
I found a similar thread below, this customer found these workarounds helpful:
Method 1: Use the Calendar Options page in OWA
1. Log into your mailbox using OWA
2. Click Options
3. Click Calendar Options
4. Scroll down to the "Automatic Calendar Processing" section
5. Disable the "Always place new meeting requests tentatively on my calendar"
checkbox and click Save.
Method 2: Use the Exchange Management Shell
1. start the Exchange Management Shell
2. run the following command: Set-MailboxCalendarSettings <mailbox name> -AddNewRequestsTentatively:$False
The thread is below:
https://social.technet.microsoft.com/forums/office/en-US/44093e33-133d-4de7-9f67-9ec591453bd0/calendar-meeting-time-zone-display-issue
Regards,
Melon Chen
Forum Support