Thank you for your post.
When you go to export, at the bottom of the options at the bottom of the "Specify Field Order" has a checkbox that says "Apply current layout's data formatting to exported data". When you check this option, the data will be exported using the field format. Therefore, all 24 hour times that are displayed in 12 hour format (using field format) will export consistently in the 12 hour format.
You can use this in a script step, so you don't have to worry about checking this option each time you export.
Thank you very much!