If your colony is well established and you have solid animals it does not matter.
I clean rodents on Thursdays no exception, whether some might be 5 days old, one day old, 1 hour old, or being born everything get cleaned up.
Ok just making sure. I usually change it every 5 days for the adults. Didn’t want to rush things. I’ll go ahead and change it. Looks like my black male passed on his color to some of the litter.