It is my experience that the CSRs contain cards stating that this person is recorded on a Receipt Roll for Clothing for the 1st, 2nd, 3rd, 4th Quarter, etc. Usually there is nothing else noted, nor date given.
It appears that clothing issues occurred quarterly. I have no idea if they were scheduled on any given date. However, I would believe that they occurred when the opportunity arose.
Regulations stated: "Ordinarily the company commander will procure and issue clothing to his men twice a year, at other times when necessary in special cases."
I would say you're lucky that you can pinpoint a number of men during a three month period of 1864. My ggrandfather's regiment has no such records extant, post June 1863, which could help define the regimental roster.