Editing Scheduled Tasks: crontab -e

Viewing current cron jobs: crontab -l

Basic Format

*    *    *    *    *    command
|    |    |    |    |    |
|    |    |    |    |    +-- Command to be executed
|    |    |    |    +------- Day of the week (0 - 6) (Sunday=0)
|    |    |    +------------ Month (1 - 12)
|    |    +----------------- Day of the month (1 - 31)
|    +---------------------- Hour (0 - 23)
+--------------------------- Minute (0 - 59)

Explanation

• The first column represents minutes (1-59). Every minute is represented by `` or /1.
• The second column represents hours (0-23, 0 means midnight).
• The third column represents days of the month (1-31).
• The fourth column represents months (1-12).
• The fifth column represents days of the week (0-6, 0 means Sunday).
• The sixth column is the command to be executed.

Example of scheduling a URL request

00 03 * * * /usr/bin/curl <http://crmpay.com/mpdown>

💡 Note: Be sure to include the full path /usr/bin/curl.

Applications

• Scheduled restart of Apache service
• Reports generation
• Automatic payment reconciliation, etc.

crontab options:

crontab [-u username] 
// Omitting the username implies operating on the current user's crontab.