Schedule both conditional and non-conditional scripts.

// Only run this Scheduled Job if there are active Incidents over 30 days old
var ga = new GlideAggregate('incident');
ga.addAggregate('COUNT');
ga.addQuery('active', 'true');
ga.addQuery('sys_created_on', '<', gs.daysAgo(30));
ga.query();
ga.next();
ga.getAggregate('COUNT') !== '0'

1. Navigate to System Definition > Scheduled Jobs.
2. Click New.
3. Select Automatically run a script of your choosing.
4. On the form, fill in the fields.

   Table 1. Schedule script execution

   Field	Description
   Name	Name that identifies this scheduled job.
   Active	Option that indicates that scheduled job is active and should be executed at the specified date and time.
   Application	Name of the application that contains the script. Global appears if the script is in the global scope.
   Conditional	Option for enabling the running of the schedule job if certain conditions are met in the associated script.
   Condition	Conditional script that determines if a scheduled job should run. The last expression of the script should evaluate to a Boolean (true/false) value. This text box appears only if you select Conditional.
   Run	Time interval to use for running the scheduled job: Daily: Runs daily, at a designated time. Weekly: Runs on a weekly basis, at a designated time and day of the week. Monthly: Runs on a monthly basis, at a designated time and day of the month. Periodically: Runs on a designated repeating interval. Once: Runs for a single occurrence only. On Demand: Runs immediately on demand. Business Calendar: Entry Start: Runs on the starting entry dates for the business calendar you select in the Business Calendar field. A scheduled job runs for the starting date of each of the business entries you defined for the business calendar. For example, if the business calendar represents a fiscal year, and the starting date of each entry is a fiscal month, the scheduled job runs on the first day of each month. Business Calendar: Entry End: Runs for the ending date for the business calendar you select in the Business Calendar field. This selection runs in the same manner as Business Calendar: Entry Start, but for end dates of associated business calendar entries.
   Day	Day on which the scheduled job should run. If Run is set to Weekly, select the day of the week. For example, select Wednesday. If Run is set to Monthly, select the day of the month. For example, select 25 for the 25th day of the month. This field only appears if you select Monthly or Weekly in the Run field.
   Repeat Interval	Duration of the repeat interval for each scheduled job execution. Enter the duration in the number of days, hours, or minutes. For example: To run the scheduled job every four days, enter 04 into the Days field. To run it every 26 hours, enter 26 into the Hours field. If it should repeat at an interval of 13:30:25, enter 13 into the Hours field, then 30 and 25 into the two unlabeled fields after it.
   Time zone	Time zone to use with the Time field entry when you specify the time at which the scheduled job run. Select a time zone entry: -None-: Use the default time zone for the logged in user who is creating the scheduled job. For example, the scheduled job runs at 04:45 p.m. US/Pacific time if it is the user's assigned time zone, and you enter 16:45 into the Time field. Use System Time Zone: Use the default system time zone specified for the instance in which it runs. For example, the scheduled job runs at 10:15 p.m. London time if Europe/London is the default system time zone for the instance, and you enter 22:15 into the Time field. Actual time zone. For example, the scheduled job runs at 1:30 p.m. in the US Eastern time zone if you select US/Eastern, and enter 13:30 into the Time field.
   Time	Time of day at which the scheduled job should run, expressed in hours, minutes, and seconds on a 24-hour clock. The selection you make in the Time zone field determines the time zone for this entry.
   Starting	Date and time of the first scheduled job generation. Select the calendar date and time. This field only appears if you select Periodically in the Run field.
   Run as [Optional]	Select another user to run the script execution as. Configure the form to add this field if it is not present.
   Run this script	Name of the script to run at the scheduled date and time. For example, copy script logic from a business rule, or call a script include.