iCal invite for ServiceNow calendar integration shows incorrect dates

When users are sent any Calendar notification email, the date for the calendar invite is the same as the moment of submission of the record and not for the time selected for the invite

This happens because of incorrect mapping of start_date and/or end_date fields for corresponding dtstart or dtend as needed in the sys_impex_map table.

This can be corrected by the following steps:

1. Check for the relevant table in the sys_impex_map table.
2. If there is no entry, then create New entry with the following values and save
   1. Name: Use the following naming convention: icalendar.<table name>. For example,icalendar.u_my_custom_table.
   2. Table: Select the custom table you created
   3. Type: Select icalendar
3. In the field maps related list create New field mapping for date fields
4. In the Mapping Entry Wizard, select Mapping to a Database Field.
5. Create field mappings for dtstart and dtend. These variables are required. For example, map the External Name dtstart to the u_meeting_start_time field in u_my_custom_table.
6. Click Submit.
7. Create field mappings for any other iCalendar fields as necessary and click Update
8. Once the field mappings are created, then create an email template that defines the icalendar invitation. 
9. In the message text field, mention the date fields like this:

   DTSTART:${dtstart}
   DTEND:${dtend}

10. Following this ensure that the existing email notification / create new email notification with the type as Meeting invitation, content type as Plain text only and Email template set as the one which was just created.

Even if it is a system table like change_request, and there is no entry in the sys_impex_map table, then it can be created in the same way.

The ${dtstart} and ${dtend} would now point to the correct time of the invite and not the creation time of the record.