Incorrect Create/Modify date for some audio files

[Alex Kliuchnikau]

For some audiofiles I get incorrect create/modify date - date from the future. For example for the attached file I get the following output:

> exiftool original_audio.m4a
...
Create Date                     : 2039:08:19 19:26:06
Modify Date                     : 2039:08:19 19:26:06
..

I tested this issue on Mac OS X Mountain Lion and Ubuntu 12.04 LTS. Latest exiftool 9.36 and some old versions 8.60 and 9.13.

I received these files from the customer and I don't know real create date. These files were captured by iPhone 5. Please let me know if you need more information - I'll try to get it from the author of this audio sample.

Sample audio file: https://www.dropbox.com/s/dj3v4clhsi79r74/original_audio.m4a

[Phil Harvey]

The hex value stored for these dates is 0xff1f45ce.  If this is interpreted as seconds since Jan 1, 1970 (the standard way date/times are encoded), then the date is as reported.

- Phil