crontab 同时显式指定day of month和day of week的特殊说明
man 5 crontab:
field allowed values
----- --------------
minute 0-59
hour 0-23
day of month 1-31
month 1-12 (or names, see below)
day of week 0-7 (0 or 7 is Sun, or use names)
more ...Note: The day of a command's execution can be specified by two fields -- day of month, and day …