Set Of More DOS Utilities v56.0a recent date\time upgrade notes:

If any combination of /1, /2, and /3 are used, each switch is used for:

 /1  creation date\time
 /2  last access date
 /3  last modified date\time

Except Copyit which uses /7, /8, and /9, respectively.

Some utilities use the switch for date\time displays. They are listed in
the order of /1 to /3. Some utilities use these switches for date\time
comparisons, and can any combination of all three. Finally, some utilities
only use the first switch specified but all switches can be used.

For a windows dos box, the creation date\time, last access date and last
modified date\time can be used. And are listed in that order.

In plain dos 7.10, only the last modified date\time and last access date
can be used. The last access date will follow the last modified date\time
in parenthesis. And will be listed in that order.

In dos versions prior to 7.10 only the last modified date\time can be used.

If the date\time switches are not specified then all utilities default to
use the file last modified date\time.

Last access date has no time stored to compare, it is always 00:00:00.

Last modified (write) time has no seconds and is rounded to the minute.

The root directory is always 01/01/1980 00:00:00 for all date\times.

Also note that the creation date\time includes a millisecond storage area.

The milliseconds are stored in tenths (one-hundredth units) and range from
0 to 199 hundredths. This is because the time is stored in 5 bits, making
the total storage for seconds 0 to 31. And since DOS stores the seconds
divided by two to fit the bit area, DOS rounds the seconds to any multiple
of 2. Thus, adding 0 to 199 tenth-milliseconds rounds the seconds back to
any specific value by adding 0 to 1.99 seconds.

In dos 7.10 or previous the time seconds can be set to 60 or 62 and stored
in 5 bit format, because the seconds are divided by 2. Which is also why the
seconds display is always a factor of 2. However windows will return with an
access denied error if the seconds is set to 62.

The dos DIR command displays the last modified and last accessed date\time:

For example, using DIR DTA.BI /V displays the date\time similar to the
above utility descriptions:

 Modified             Accessed
01-01-1980  4:30pm   01-01-1980

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