Camp time

Camp time is a setting that can be set in the troop-deployment window. If you click on a city, valley, or NPC, and select one of the options that lets you send troops to that location, you can also set something called camp time. Basically, what it does is let your troops wait for a time that you defined before actually attacking or whatever you chose.

Strategical Attacking
Camp time is very useful for spamming other cities or advanced strategic moves. A player can deploy waves to hit a city at exactly the same second, which is very useful for wiping cities of troops in a short amount of time to let loyalty waves hit before reinforcements arrive.

Farming
Camp time is also very useful for NPC Farming, epecially level 10 NPCs where you have to wait for troops to respawn in order to get a drop. You can send all the waves that are meant to hit in the next hour or so in a minute, using camp time to let them wait for a few minutes before attacking. This is very useful if you are farming from several cities, as it lets you do other stuff than sending each wave one by one at the right time.

Time Hopping Attacks
Camp time makes advanced strategies like Time Hopping Attacks a lot easier, and you can focus on your attack reports rather than sending new waves at exactly the right second.

Spam attacks
Camp time is also useful for scheduling so-called spam attacks, as you can send the maximum number of waves that your Rally spot allows at once and schedule them to arrive with defined gaps. It can also be set to 23 hours and 59 minutes, which lets the spammed players' reports blink red for the next ca 24 hours. This does not have any effect on the wave, except that it may annoy the victim of the spamming a bit.