Haymaking is the process of taking the fresh cut grass and turning it into hay fodder ready for building into a haycock. The process of haymaking for a bale is similar but the hay must be drier and and more seasoned before attempting to bale it, particularly for square bales. Grass cut for silage by contrast only requires minimal drying before being baled before taken to a pit.
There is an adage make hay while the sun shines. If the sun is shining and hot and the field open and especially with a gentle breeze the grass will turn to hay with relatively little work and trouble. If the weather turns wet and cold and the field is shady and the days less long saving the hay will become much more difficult.