All the production times in Hay Day are setwith increasing difficulty in mind– the higher you level up the harder the farm tasks get.
When you first start the game, the items such as wheat and corn have lower production times to allow all the new players to progress at a reasonable pace. The further players progress in the game, the more difficult the orders become and the bigger the rewards get.
Each time you gain a level, the amount of experience needed to attain the next level will rise. By adjusting the production time and the rewards you gain for each product, the game remainsbalancedand fun for everyone.
Of course there is a choice for everyone to use diamonds to speed up processes, so that the pace of progression is entirely up to the player.