[Finalizing] Make sure the schedule you created is Finalized and not just Saved.

Remember to use the lock icon to Finalize your schedule when you've finished.
If you saved the schedule but did not click the lock icon to Finalize, you can use the Finalize Log utility under Programming > Scheduling > Utilities > Finalize Log.

[Settings] Adjust the number of days forward (or backward) users can browse the log.

A Station or Market administrator can adjust this setting under Setup > InStudio > Restrictions.
Select the number of days back or ahead to browse. (PromoSuite Next's default settings are 7 days forward and 7 days behind.)