Sure, you can't remove all risk, but you can reduce it and reduce the risk of unexpected firefighting work. You can implement rolling or blue/green deployments that roll-back on failure. The key is being able to identify failures, which means having meaningful canaries to identify issues. Those canaries can also improve your operational awareness so they aren't just a deployment investment.
If you don't deploy on Friday then you lose 20% of your deploy opportunity. If you only deploy once or twice a week, then sure - choose Monday/Wednesday or something, but if you deploy more frequently then improve your deployment safety.
If you don't deploy on Friday then you lose 20% of your deploy opportunity. If you only deploy once or twice a week, then sure - choose Monday/Wednesday or something, but if you deploy more frequently then improve your deployment safety.