介绍一个参数，这个参数差不多可以在所有以文件为操作对象的 4DOS 命令中使用
4DOS Help Topic: Time Ranges
A time range specifies a file modification time without reference to the
date. For example, to select files modified between noon and 2:00 pm on any
date, use /. The times in a time range can either be in
12-hour format, with a trailing "a" for AM or "p" for PM, or in 24-hour
format.
If you omit the second argument in a time range, you will select files that
were modified between the first time and the current time, on any date. You
can also use offsets, beginning with a plus sign or a minus sign for
either or both of the arguments in a time range. The offset values are
interpreted as minutes. Some examples:
Specification Selects Files
/ modified between noon and 2:00 PM on any date
/ modified between two hours ago and the current
time on any date
/ modified in the morning on any date
The standard FAT file system maintains a single time for each file,
reflecting the last time the file was written. This is the time used by
4DOS on a FAT drive with no LFN support (e.g. under MS-DOS 6.22, PC DOS 7.0
or 2000, DR-DOS 7.03 without LONGNAME loaded, or OS/2).
Drives which support long filenames (e.g. under Windows 95/98/ME, or under
plain DOS with a suitable LFN driver loaded) maintain 3 sets of dates and
times for each file: creation, last access, and last write (for last access
only the date is recorded; the last access time is always returned as
00:00). By default, time ranges work with the last write time stamp. You
can use the "last access" (a) or "created" (c) time stamp in a time range
with the syntax:
/ or /
如按照你具体的需求：修改时间大于七点三十分小于晚八点十五分
可以这样
copy /s / ... ...
或
del /s / ...
