The “Ignore Time” option can be used to ignore the modification time of files in the directory comparison.
Date and time are two separate options: ignoring the time alone still compares the day. The effect on the comparison is the one described under Ignore Date — the fewer attributes decide, the more often the file contents do.
Ignore Time is the option to reach for when comparing a folder against an archive: many archive formats store times with a two-second resolution, so entries that came from exactly these files can still show a one-second difference.