The livelong day
Definition 1 of 1
Pro Tip 1/3Archaic Usage
The phrase 'the livelong day' is old-fashioned and rarely used in modern conversation. 
Grandpa would recite tales of how he toiled in the fields the livelong day.
Pro Tip 2/3Emphasizing Duration
Use 'the livelong day' to emphasize that something continues for an extended and uninterrupted period. 
The child played with his new train set the livelong day.
Pro Tip 3/3Literal vs. Metaphor
This phrase can be literal or metaphorical; it might not exactly mean from sunrise to sunset. 
She waited for the courier the livelong day, though it was just a few hours.