Normally, you have to wait for your crops to be ready to harvest, your mill to produce feed for the cows, chickens and other animals, and for your animals to produce their products, etc. So to speed things up you can set the time on your phone to few hours ahead or more to get such processes finished instantly. Afterward, go back to the game and collect everything, then set your time back to normal. However, if you do not collect everything first, the uncollected items will go back into the waiting period after you set your time back to normal. Note: This may not working on all versions.