Cron expression is a string that defines a schedule for running a task or job at specified times. It consists of six fields that represent the following values, in order.
Cron expressions can also include special characters such as '/', '-', and ',' to specify more complex schedules. For example, '0 0 12 */2 * *' represents a schedule that runs every other day at noon.
Cron expressions are widely used in job scheduling and can be used with a variety of programming languages and platforms. In C#, libraries such as NCrontab can be used to parse and calculate cron expressions.
Example:
Sample Windows Service Job Scheduling Application that uses a Cron Expression
Each field can be either a specific value, a range of values, or a wildcard '*' to represent all values. For example, '0 0 * * * *' represents a schedule that runs every hour at the beginning of the hour, while '0 0 12 * * *' represents a schedule that runs every day at noon.
- * * * * * *
- - - - - - -
- | | | | | |
- | | | | | +----- day of the week (0 - 6) (Sunday = 0)
- | | | | +---------- month (1 - 12)
- | | | +--------------- day of the month (1 - 31)
- | | +-------------------- hour (0 - 23)
- | +------------------------- minute (0 - 59)
- +------------------------------ second (0 - 59) [optional]
Cron expressions can also include special characters such as '/', '-', and ',' to specify more complex schedules. For example, '0 0 12 */2 * *' represents a schedule that runs every other day at noon.
Cron expressions are widely used in job scheduling and can be used with a variety of programming languages and platforms. In C#, libraries such as NCrontab can be used to parse and calculate cron expressions.
Example:
Sample Windows Service Job Scheduling Application that uses a Cron Expression