A time window is the period of time during which a task can begin on any scheduled run day. For example, if you schedule a task to run every Monday, the task can start at or anytime after midnight early Monday morning. It cannot, however, start after 11:59:59 PM Monday night.
The "Not in time window" occurs if the Backup Exec is unable to start the job within given time limit OR the time window specified for the backup job is overlapping with another job. Refer to the following example for better understanding:
Example:
You have configured a backup job named back1. Which starts at 9:00PM and finishes at 11:00 PM? You have configured another backup job named back2 and specified the time window 10:00PM and 10:30PM. In that case back1 finishes at 11:00 PM. So, Backup Exec will unable to start the backu2 within given time limit (i.e. 10:00PM and 10:30PM). Therefore, back2 will result is "Not in time window" status.
To resolve the issue, change the schedule of backup jobs in such a way that their backup time window does not get conflict with another backup job.