ExifTool Forum

ExifTool => The "exiftool" Application => Topic started by: mahikeulbody on July 30, 2024, 12:59:06 PM

Title: How to add a time zone info to a date field of a QuickTime video ?
Post by: mahikeulbody on July 30, 2024, 12:59:06 PM
Hi,
Date fields of a quicktime video are presumed to be UTC time and generally they have not time zone associated.
Is it possible to add a specified time zone to these fields with exiftool ? (in order to transform these dates into local dates)
Title: Re: How to add a time zone info to a date field of a QuickTime video ?
Post by: StarGeek on July 30, 2024, 05:43:24 PM
No.  The Quicktime:CreateDate, Quicktime:ModifyDate, and all the Track*Date/Media*Date tags are UTC. You cannot add a time zone to them. This is true of any date/time tag that is listed as an "integer" on the Quicktime tags page (https://exiftool.org/TagNames/QuickTime.html).

The Quicktime:DateTimeOriginal and Quicktime:CreationDate are supposed to be set to local time and by default, exiftool will add the local time zone, though you can set any time zone you want when writing the time stamp. The reason exiftool will automatically add a time zone to these is because in the past, Apple Photos would give you wildly inaccurate date/times (https://exiftool.org/forum/index.php?msg=64363) unless a time zone was included.  I don't know if that is still a bug.
Title: Re: How to add a time zone info to a date field of a QuickTime video ?
Post by: wywh on July 31, 2024, 07:04:22 AM
Quote from: StarGeek on July 30, 2024, 05:43:24 PMThe reason exiftool will automatically add a time zone to these is because in the past, Apple Photos would give you wildly inaccurate date/times (https://exiftool.org/forum/index.php?msg=64363) unless a time zone was included.  I don't know if that is still a bug.

This was fixed in macOS 13 Ventura and later.

exiftool -ver 12.13 and later automatically adds time zone unless -n option is used.

- Matti
Title: Re: How to add a time zone info to a date field of a QuickTime video ?
Post by: mahikeulbody on July 31, 2024, 07:33:01 AM
Quote from: StarGeek on July 30, 2024, 05:43:24 PMNo.  The Quicktime:CreateDate, Quicktime:ModifyDate, and all the Track*Date/Media*Date tags are UTC. You cannot add a time zone to them. This is true of any date/time tag that is listed as an "integer" on the Quicktime tags page (https://exiftool.org/TagNames/QuickTime.html).

The Quicktime:DateTimeOriginal and Quicktime:CreationDate are supposed to be set to local time and by default, exiftool will add the local time zone, though you can set any time zone you want when writing the time stamp. [...]

Thank you for the answer.