Cron 表达式

 

Field Name	Mandatory	Allowed Values	Allowed Special Char
Seconds	YES	0-59 , - * /
Minutes	YES	0-59 , - * /
Hours	YES	0-23 , - * /
Day of month	YES	1-31 , - * ? /	L W C
Month	YES	1-12 or JAN-DEC , - * /
Day of week	YES	1-7 or SUN-SAT , - * ? /	L C #
Year	NO	empty, 1970-2099 , - * /

  　 　　　　
  　

所有星号对应的段位置，都可以出现后面的符号（, - * /）
（? / L C）这些符号可以出现在"一月哪天"和"星期"段位置
（w）只能出现在"一月哪天"段位置
（#）只能出现在"星期"段位置

解释符号代表的意思：
* 代表任意合法的字段
0 * 17 * * ? ：表示在每天的5 PM 到 5:59之间的每一分钟启动scheduler

? 表示没值被指定
如果同时指定"一月哪天"和"星期"，可能两者对应不起来
0 0,15,30,45 * * * ? ：表示每刻钟启动scheduler
所以推荐用法是其中一个指定值，另一个用?指定

/ 表示时间的增量
0 0/15 * * * ? ：表示每刻钟启动scheduler

- 表示值的范围
0 45 3-8 ? * *

L 如果用在"一月哪天"段上，表示一个月的最后一天；如果用在"星期"段上。表示一个星期的最后一天（星期六）
0 0 8 L * ? ：表示每个月最后一天的8点启动scheduler

W 表示最靠近给定时间的一天，（必须是星期一到星期五）

# 例如 6#3表示一个月的第三个星期五

 

 

The '*' character is used to specify all values. For example, "*" in the minute field means "every minute". The '?' character is allowed for the day-of-month and day-of-week fields. It is used to specify 'no specific value'. This is useful when you need to specify something in one of the two fileds, but not the other. See the examples below for clarification.  The '-' character is used to specify ranges For example "10-12" in the hour field means "the hours 10, 11 and 12".  The ',' character is used to specify additional values. For example "MON,WED,FRI" in the day-of-week field means "the days Monday, Wednesday, and Friday".The '/' character is used to specify increments. For example "0/15" in the seconds field means "the seconds 0, 15, 30, and 45". And "5/15" in the seconds field means "the seconds 5, 20, 35, and 50". Specifying '*' before the '/' is equivalent to specifying 0 is the value to start with. Essentially, for each field in the expression, there is a set of numbers that can be turned on or off. For seconds and minutes, the numbers range from 0 to 59. For hours 0 to 23, for days of the month 0 to 31, and for months 1 to 12. The "/" character simply helps you turn on every "nth" value in the given set. Thus "7/6" in the month field only turns on month "7", it does NOT mean every 6th month, please note that subtlety. The 'L' character is allowed for the day-of-month and day-of-week fields. This character is short-hand for "last", but it has different meaning in each of the two fields. For example, the value "L" in the day-of-month field means "the last day of the month" - day 31 for January, day 28 for February on non-leap years. If used in the day-of-week field by itself, it simply means "7" or "SAT". But if used in the day-of-week field after another value, it means "the last xxx day of the month" - for example "6L" means "the last friday of the month". When using the 'L' option, it is important not to specify lists, or ranges of values, as you'll get confusing results.The 'W' character is allowed for the day-of-month field. This character is used to specify the weekday (Monday-Friday) nearest the given day. As an example, if you were to specify "15W" as the value for the day-of-month field, the meaning is: "the nearest weekday to the 15th of the month". So if the 15th is a Saturday, the trigger will fire on Friday the 14th. If the 15th is a Sunday, the trigger will fire on Monday the 16th. If the 15th is a Tuesday, then it will fire on Tuesday the 15th. However if you specify "1W" as the value for day-of-month, and the 1st is a Saturday, the trigger will fire on Monday the 3rd, as it will not 'jump' over the boundary of a month's days. The 'W' character can only be specified when the day-of-month is a single day, not a range or list of days . The 'L' and 'W' characters can also be combined for the day-of-month expression to yield 'LW', which translates to "last weekday of the month". The '#' character is allowed for the day-of-week field. This character is used to specify "the nth" XXX day of the month. For example, the value of "6#3" in the day-of-week field means the third Friday of the month (day 6 = Friday and "#3" = the 3rd one in the month). Other examples: "2#1" = the first Monday of the month and "4#5" = the fifth Wednesday of the month. Note that if you specify "#5" and there is not 5 of the given day-of-week in the month, then no firing will occur that month. The 'C' character is allowed for the day-of-month and day-of-week fields. This character is short-hand for "calendar". This means values are calculated against the associated calendar, if any. If no calendar is associated, then it is equivalent to having an all-inclusive calendar. A value of "5C" in the day-of-month field means "the first day included by the calendar on or after the 5th". A value of "1C" in the day-of-week field means "the first day included by the calendar on or after sunday".