You can add only optional periodic jobs.
Go to the
Configuration menu → > Integration → > Periodic Jobs. 
Click the Add button on top of the Periodic Jobs table. You will be directed to the Add page.
Select the periodic job’s Type:
Client Invoicing → - filters and selects the tasks that will be automatically added to new Client Invoices within the configured time frame. To learn more about this periodic job, see the Automatic Client Invoicing article.
Filter Subscription → - pulls data from a browsing view with any filter combination applied to it and sends the filtered data to the list of email subscribers.
Macro Subscription → - runs a macro and sends the results to a specified Home Portal user.
Overdue Invoices Reminder → - sends notifications to a specified Home Portal user and, optionally, to the invoice signatory and the PM responsible for the jobs related to the overdue invoices.
Report Subscription → - pulls data from reports and sends it to the list of email subscribers.
Time Control Synchronization Job →- aggregates the work logs of selected groups for the selected time period and sends the summary to the recipients.
Vendor Invoicing
The Text Message Delivery Check and WeLocalize Synchronization periodic jobs are deprecated.
Provide a name for the new periodic job.
Click the Save button. You will be directed to the Periodic Job page.
In the Job Configuration section, select or provide the desired settings.
This section’s content depends on the periodic job type.In the Execution Configuration section, decide when and how often the job has to be executed:
With the radio button, select one of the options:
Daily
Days per Week
Days per Month
Advanced
(For Daily and Days per Week options) From the Type drop-down list, select whether the job will be executed Once per day or Periodically.
Use the fields below to specify the desired schedule.
(For Advanced) Provide the appropriate Cron Expression.
In the Periodic Job Statistics section, you can check
The Number of Executions
Last Execution Time
Available logs for this job.
Click the Save button to confirm the changes.