Cron expression "two"

A cron expression is a string of characters separated by 5 or 6 spaces, divided into 6 or 7 fields, each of which represents a meaning, and Cron has the following two syntax formats:

Seconds Minutes Hours dayofmonth Month DayofWeek year or
Seconds Minutes Hours dayofmonth Month DayofWeek

The following characters can appear for each field:
Seconds: Can appear ",-*/" four characters, valid range is 0-59 integer
Minutes: Can appear ",-*/" four characters, valid range is 0-59 integer
Hours: Can appear ",-*/" four characters, valid range is 0-23 integer
DayOfMonth: Can appear ",-*/? L W C "Eight characters, integer with valid range 0-31
Month: Can appear ",-*/" four characters, a valid range of 1-12 integers or jan-dec
DayofWeek: Can appear ",-*/? L C # "Four characters, a valid range of 1-7 integers or Sun-sat two ranges. 1 means Sunday, 2 means Monday, and so on
Year: Can appear ",-*/" four characters, valid range is 1970-2,099 years

Each field uses numbers, but the following special characters can appear, meaning:
(1) *: Indicates any value that matches the field, and if you use * in the Minutes domain, the event will be triggered every minute.

(2)?: can only be used in DayOfMonth and DayOfWeek two domains. It also matches any value of the field, but it does not. Because DayOfMonth and DayOfWeek will affect each other. For example, to trigger a schedule on the 20th of each month, regardless of whether the 20th is the day of the week, you can only use the following: 13 13 15 20 *?, the last one can only be used? , but not with *, if using * means that the day of the week will trigger, in fact it is not.

(3)-: Indicates a range, for example, using 5-20 in the Minutes domain, indicating that it is triggered every minute from 5 minutes to 20 minutes

(4)/: Indicates that the start time starts triggering and then fires once every fixed time, such as using 5/20 in the Minutes domain, which means that 5 minutes is triggered once, and 25,45 is triggered separately.

(5),: Indicates that the enumeration value value is listed. For example, using 5,20 in a minutes domain means firing at 5 and 20 minutes per minute.

(6) L: Indicates that finally, only in the DayOfWeek and dayofmonth domains, if 5L is used in the DayOfWeek domain, it means that it is triggered in the last Thursday.

(7) W: Indicates a valid weekday (Monday to Friday) that can only appear in the DayOfMonth domain, and the system will trigger the event on the most recent active weekday from the specified date. For example: Use 5W in DayOfMonth, if 5th is Saturday, it will be triggered on the most recent weekday: Friday, 4th. If 5th is Sunday, it will be triggered on 6th (Monday) and if 5th is one day from Monday to Friday, it is triggered on 5th. Another point, W's recent search won't cross the month

(8) LW: These two characters can be used together, indicating the last working day of the month, that is, the last Friday.

(9) #: Used to determine the number of weeks per month, can only appear in the DayOfMonth domain. For example in 4#2, which represents the second Wednesday of a month.

For a few examples:
0 0 2 1 *? * Indicates a scheduled task at 2 o'clock in the morning on the 1st of each month
0 15 10? * Mon-fri represents Monday to Friday daily 10:15 execution of jobs
0 15 10? 6L 2002-2006 represents the last Friday 10:15 of the month of 2002-2006 to be executed as

A cron expression has at least 6 (or possibly 7) time elements that have a space separation.
In order of
Seconds (0~59)
Minutes (0~59)
Hours (0~23)
Days (months) (0~31, but you need to consider the number of days of your month)
Month (0~11)
Days (weeks) (1~7 1=sun or Sun,mon,tue,wed,thu,fri,sat)
Year (1970-2099)

Each of these elements can be a value (such as 6), a continuous interval (9-12), a time interval (8-18/4) (/= every 4 hours), a list (1,3,5), and a wildcard character. Because the two elements of the date in the month and the days in the week are mutually exclusive, one of them must be set?

0 0 10,14,16 * *? 10 o'clock in the morning, 2 o'clock in the afternoon, 4 O ' Day
0 0/30 9-17 * *? Every half hour for nine to five working hours
0 0 12? * WED means every Wednesday noon 12 o'clock
"0 0 12 * *?" trigger 12 o'clock noon every day.
"0 15 10?" * * "trigger 10:15 every day"
"0 15 10 * *?" Daily 10:15 Trigger
"0 15 10 * *?" * "10:15 per day" trigger
"0 15 10 * *?" 2005 "2005-year daily 10:15 Trigger
"0 * 14 * *?" triggers every 1 minutes from 2 o'clock in the afternoon to 2:59 daily
"0 0/5 14 * *?" triggers every 5 minutes from 2 o'clock in the afternoon to 2:55 daily
"0 0/5 14,18 * *?" triggers every 5 minutes from 2 o'clock in the afternoon to 2:55 daily and from 6 o'clock in the afternoon to 6:55
"0 0-5 14 * *?" triggers every 1 minutes from 2 o'clock in the afternoon to 2:05 daily
"0 10,44 14?" 3 WED "2:10 and 2:44 triggers in Wednesday of every March
"0 15 10?" * Mon-fri "Monday to Friday 10:15 trigger
"0 15 10 15 *?" 15th 10:15 per month
"0 L *?" 10:15 on the last day of the month
"0 15 10?" * 6L "Last month of Friday 10:15 Trigger
"0 15 10?" * 6L 2002-2005 "2002 to 2005 the last of the monthly Friday 10:15 trigger
"0 15 10?" * 6#3 "Monthly third Friday 10:15 trigger

Some sub-expressions can contain ranges or lists

For example: subexpression (Day (week)) can be "Mon-fri", "Mon,wed,fri", "Mon-wed,sat"

The "*" character represents all possible values

Therefore, "*" in the sub-expression (month) represents the meaning of each month, "*" in the subexpression (Day (week)) represents every day of the week

The "/" character is used to specify the increment of the numeric value
For example: "0/15" in sub-expressions (minutes) means starting from the No. 0 minute, every 15 minutes
"3/20" in the sub-expression (minutes) means that every 20 minutes (it is the same as "3,23,43") starting from the 3rd minute

“？ "Character is used only for days (months) and days (weeks) of two sub-expressions, indicating that no value is specified
When one of the 2 sub-expressions is assigned a value, in order to avoid a conflict, you need to set the value of another subexpression to "? ”

The "L" character is used only for days (months) and days (weeks) of two sub-expressions, which is the abbreviation for the word "last"
But it has a different meaning in two sub-expressions.
In the day (month) subexpression, "L" represents the last day of the one-month
In the day (week) Self-expression, "L" represents the last day of one weeks, the SAT

If there is something specific before "L", it has other meanings.

For example: "6L" means the 6th day of the month, and "Fril" means the last Friday of the month.
Note: When using the "L" parameter, do not specify a list or range, as this can cause problems

Special characters allowed for field allowed values
Seconds 0-59,-*/
Sub 0-59,-*/
Hours 0-23,-*/
Date 1-31,-*? /L W C
Month 1-12 or JAN-DEC,-*/
Week 1-7 or Sun-sat,-*? /L C #
Year (optional) leave blank, 1970-2099,-*/

Cron expression "two"