Ni un martillazo más / Es hora de echar la hamaca

Pictures taken from Google Images, «Call it a day»
Click on the image to watch the trailer of the movie, «The Night We Called it a Day»

Meaning:

This idiom means that it is time to stop work.

Pictures taken from Google Images, «Call it a day»
Click on the image to watch the video of the song «Call it a day» by Rachel Talbott

Origin:

People start the day working and spend most of the day working as well. Then, when we call it a day, we mean that it has been enough work for one day and it is time to go home to relax and to save energy for tomorrow´s workday. This idiom could have been coined in the XIX century when people devoted most of their to work.

Pictures taken from Google Images, «Call it a day»
Click on the image to watch the video fo «Call it a day promo Summer 2013» by Gucci Submarine

Example: