I have created a list of pages for various program activities (fitness, aquatics, day camp programs etc.) on my Drupal site. For each program activity such as Fitness, there are classes listed under each day of the week so it displays something like this:

Fitness Programs:

Day Timestamp: Monday
-Teen Strength & conditioning Centre Orientation
-Step & Strength

Day Timestamp: Tuesday
-Zumba
-Cyclefit
.....

Day Timestamp: Sunday
-Personal Training
-Yoga

I've set up in Administer>Site building>Views to group field and sort by "Day Timestamp" (sorting from Monday to Sunday) for each program page. I've applied the same group field and sort settings to all of the various programs on my site and most of them are sorting correctly from Monday to Sunday except 2 of them. It would display the days of the week out of order ( Tues, Thurs, Sat, Fri, Wed..) I've checked the SQL database tables to see if the days of the week were entered incorrectly in case there were different ASCII characters that may lead to wrong sorting order. This did not work either. Would anyone be able to assist or make any suggestions to correct this?

Thanks!