[541] ProDOS の日時形式。

[6] 関連: 西暦2000年問題

• [542] Time formatting and storage bugs - Wikipedia, 2023-11-24T03:13:21.000Z, 2023-11-25T07:09:30.539Z https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2040
• [543] ProDOS 8 Technical Note #28, 2009-04-30T19:44:01.000Z, 2023-11-25T07:09:44.626Z http://www.1000bit.it/support/manuali/apple/technotes/pdos/tn.pdos.28.html

[544] ProDOS 2.5 Alpha 8, 2023-01-21T22:14:08.000Z, 2023-11-25T07:10:33.840Z https://prodos8.com/releases/prodos-25/

[3] >>544

Year has been expanded from 7-bits (127 years) to 10-bits (1,024 years) to allow date support until the year 2924. There is still a year 2040 problem where the 24-bit timer on the Apple IIgs will wrap around to 1900.

[5] >>544

year = 0-4095

[2] >>544

• The Legacy data format uses 4 bytes (32-bits) to store the date and time.
• The Extended data format uses 4 bytes (32-bits) to store the date and time for directory listings.
• The Extended data format uses 6 bytes (48-bits) to store the date and time for global entries.

[1] >>544

milliseconds*4

milliseconds = 0-249

[4] >>544

month = 2-13

    month +1 keeps top 3 bits from being 0,
    differentiating it from pre-2.5 format