Certainly, in our own work, efficiency falls off as the week passes its mid point and many studies show that the five day week is actually more productive than the six day week in most jobs. Many sermons (on the seventh day) are quite awful. It is odd that He Who Knows All Things did not seem to know about fatigue and created us on the very dodgy sixth day. Would it not have been better for Him to have put His Feet up after five days and to have made us on the Second Monday. Perhaps He might have built in a bit less Human Fallibility that way.
We have all experienced the 'Friday Afternoon Car' - its doors don't shut properly, it never starts smartly and the gears crash without being asked to. Perhaps Sin and Fall - which we Christians see in us all - are simply that we are 'Friday Afternnon Cars'. There is no Scriptural reference to Fall or Sin among plants, birds, fishes and the other non-human life forms; this fact is surely significant. They were made before God's fatigue began to tell. It is true that God was well pleased with His Work but if He was tired then perhaps He was pleased to get shot of it rather than pleased with it.
But, wait a moment, one is not at one's best on Monday mornings. God knows that too. Carry on Believing.