crontab

# Bashshot - Solaris time-slider-like functionality for GNU/Linux implemented in bash
#minute       hour  day   week  month  user   script
00,15,30,45   *     *     *     *      root   bashshot                  | logger -t "bashshot"
01,16,31,46   *     *     *     *      root   bashshot-cleaner frequent | logger -t "bashshot-cleaner frequent"
02            *     *     *     *      root   bashshot-cleaner hourly   | logger -t "bashshot-cleaner hourly"
03            03    *     *     *      root   bashshot-cleaner daily    | logger -t "bashshot-cleaner daily"
03            04    *     *     0      root   bashshot-cleaner weekly   | logger -t "bashshot-cleaner weekly"
03            05    1     *     *      root   bashshot-cleaner monthly  | logger -t "bashshot-cleaner monthly"