If this option is set to Yes, codes like %d, %m, %Y and %u can be used in the backup destination filename. These will be replaced with the day, month year and day of the week respectively when the backup is performed. This is useful if you want to save a different backup every day, so that you can roll a system back to a previous date.

Some of the other codes that can be used are :

     %a     The abbreviated weekday name according to the  cur
            rent locale.

     %A     The  full  weekday  name  according  to the current
            locale.

     %b     The abbreviated month name according to the current
            locale.

     %B     The  full  month  name  according  to  the  current
            locale.

     %c     The preferred date and time representation for  the
            current locale.

     %C     The century number (year/100) as a 2-digit integer.

     %d     The day of the month as a decimal number (range  01
            to 31).

     %e     Like  %d, the day of the month as a decimal number,
            but a leading zero is replaced by a space.

     %E     Modifier: use alternative format, see below.

     %G     The ISO 8601 year with century as a decimal number.
            The 4-digit year corresponding to the ISO week num
            ber (see %V).  This has the same format  and  value
            as  %y,  except that if the ISO week number belongs
            to the previous or next year,  that  year  is  used
            instead.

     %g     Like  %G, but without century, i.e., with a 2-digit
            year (00-99).

     %h     Equivalent to %b.

     %H     The hour as a decimal number using a 24-hour  clock
            (range 00 to 23).

     %I     The  hour as a decimal number using a 12-hour clock
            (range 01 to 12).

     %j     The day of the year as a decimal number (range  001
            to 366).

     %k     The hour (24-hour clock) as a decimal number (range
            0 to 23); single digits are preceded  by  a  blank.
            (See also %H.)

     %l     The hour (12-hour clock) as a decimal number (range
            1 to 12); single digits are preceded  by  a  blank.
            (See also %I.)

     %m     The month as a decimal number (range 01 to 12).

     %M     The minute as a decimal number (range 00 to 59).

     %n     A newline character.

     %O     Modifier: use alternative format, see below.

     %p     Either  `AM'  or  `PM'  according to the given time
            value, or the corresponding strings for the current
            locale.   Noon  is  treated as `pm' and midnight as
            `am'.

     %P     Like %p but in lowercase: `am' or `pm' or a  corre
            sponding string for the current locale.

     %r     The  time  in  a.m. or p.m. notation.  In the POSIX
            locale this is equivalent to `%I:%M:%S %p'.

     %R     The time in 24-hour notation (%H:%M). For  a
            version including the seconds, see %T below.

     %s     The  number of seconds since the Epoch, i.e., since
            1970-01-01 00:00:00 UTC.

     %S     The second as a decimal number (range 00 to 61).

     %t     A tab character.

     %T     The time in 24-hour notation (%H:%M:%S).

     %u     The day of the week as a decimal,  range  1  to  7,
            Monday being 1.  See also %w.

     %U     The  week  number  of the current year as a decimal
            number, range 00 to 53,  starting  with  the  first
            Sunday as the first day of week 01. See also %V and
            %W.

     %V     The ISO 8601:1988 week number of the  current  year
            as  a  decimal number, range 01 to 53, where week 1
            is the first week that has at least 4 days  in  the
            current  year,  and with Monday as the first day of
            the week. See also %U and %W.

     %w     The day of the week as a decimal,  range  0  to  6,
            Sunday being 0.  See also %u.

     %W     The  week  number  of the current year as a decimal
            number, range 00 to 53,  starting  with  the  first
            Monday as the first day of week 01.

     %x     The  preferred  date representation for the current
            locale without the time.

     %X     The preferred time representation for  the  current
            locale without the date.

     %y     The  year  as  a  decimal  number without a century
            (range 00 to 99).

     %Y     The year as a decimal number including the century.

     %z     The time-zone as hour offset from GMT.  Required to
            emit RFC822-conformant dates (using "%a, %d  %b  %Y
            %H:%M:%S %z").

     %Z     The time zone or name or abbreviation.

     %%     A literal `%' character.