The Daily Grind is a series of tasks which can be completed to earn special rewards.
To access the Daily Grind, you must click the Daily Grind button in the upper right of the Kingdom screen. From there you can claim the prizes for the objectives you've completed.
Although they are worded as days, you do not have a time limit to complete them (plus, it would be really hard to meet the deadlines), nor do you need to do them in order.
The Daily Grind is available until it's expired, and then disappears forever. However there is time limit of 14 days - this limit only applies to you and is not linked to server time. Every "Day" requirement is doable, just keep upgrading to avoid being stuck by cooldowns. If you are not lucky to get a level 3 jewel anywhere then make explorations at the Jewel Crafter to get jewels and then Forge those.
Day 4 and Day 7 should be your goal to finish.
Day 1
- Upgrade Kingdom to level 10
- Defeat the 6th level in the Grasslands on Easy
- Fortify all towers to level 6
- Upgrade 2 magic skills to level 6
Rewards: 5x Earth Essence, 5x Rainbow Ore
Day 2
- Train any hero to level 12
- Battle 10 times in the Fighting Pits
- Upgrade armor 20 times
- Successfully augment 10 times
Rewards: 2x Heroic Medals, 500x Gold
Day 3
- Fortify all towers to level 12
- Sign-in successfully 3 times
- Defeat 10 Monster Den - Boss Clashes
- Own two level 2 jewels
Rewards: 5x Fairy Wood, 5x Air Essence
Day 4
- Have Robin Eagleye
- Own 1 piece of equipment level 16 or higher
- Battle 30 times in the Fighting Pits
- Fortify the Barracks 5 times
Rewards: 1x Level 20 High-Quality Gear Chest, 500x Honor Stars
Day 5
- Upgrade 2 magic skills to level 12
- Defeat the 8th level in the Grasslands on Hard
- Make 2 supply runs at the Supply Station
- Successfully augment 80 times
Rewards: 1x Big Cache, 1x Cold Wand
Day 6
- Battle 50 times in the Fighting Pits
- Challenge Blitz Acres 2 times
- Upgrade Kingdom to level 20
- Fortify Barracks 7 times
Rewards: 5x Heroic Medals, 1000x Gold
Day 7
- Sign-in successfully 7 times
- Own one level 3 jewel
- Fortify all towers to level 15
- Defeat the 8th level in the Tundra on Easy
Reward: 1x Longevity Card, 1x Dark Soul Crystal