In one example, a server farm patching system may wait until fewer users are accessing a server farm to apply a patch code set to a server application executed by a server at the server farm. The server farm patching system may identify an off-peak usage time range for a server farm describing when the server farm has an activity level below an activity threshold. The server farm patching system may apply a patch code set at an off-peak usage patching aggressiveness level indicating an off-peak upper bound percentage of servers in the server farm receiving the patch code set when within the off-peak usage time range. The server farm patching system may apply the patch code set at a peak usage patching aggressiveness level indicating a peak upper bound percentage of servers in the server farm receiving the patch code set when outside the off-peak usage time range.