Mondays could also work, since it would allow people an extra weekend to finish what they want to show. Also it will allow them to procrastinate at work.
The list of bi-weekly paychecks for 2020 is here: https://www.nfc.usda.gov/Publications/Forms/1217n_20.pdf
Meaning that June's thread should be on the 20th. July on the 18th. August on the 15th. September on the 12th. October on the 10th.