Joshua 10:13b "and hasted not to go down about a whole day."
The word for "whole" is Strong's 8549 tamiym (taw-meem') תמים complete, full, whole, virgin, upright, perfect.
The word for "about" is ןכל
It's meaning is a range of light colors. Thus probably means from morning light to dusk.
The word for "day" is yowm (yome); Strongs 3117, from an unused root meaning "to be hot". Literally a day (as in the warm hours).

Joshua 10:13 "And the sun stood still, and the moon stayed, until the people had avenged themselves upon their enemies. Is not this written in the book of Jasher? So the sun stood still in the midst of heaven, and hasted not to go down about a whole day."

Literally "the sun stood still from the half of heaven" must mean the sun moved 180° east to the other half of heaven to appear to stand still in the noon position. This must mean the sun stood still for 12 hours, a whole day.
John 11:9 "Jesus answered, Are there not twelve hours in the day?"
When Joseph was made governor over Egypt March 31 2357 BC China was troubled by the sun standing still, perhaps the fulfillment of Joseph's second dream, Genesis 37. Yao employed Yin to shoot 9 arrows at the sun at which it moved again and Yao was made emperor. Then Yao immediately employed his astronomers to determine the four seasons with the correct four stars. This Chinese zodiac from 2357 BC, depicts the sun in the east in spring, that is, earth in a reverse orbit. See Joseph/Yao's long day. Logically if the sun moved 180° earth would flow into a clockwise, reverse, orbit. The four stars these astronomers determined to mark the season could not have been seen at night fall on the equinoxes and solstices because they would normally have been 10° west of the meridian when they appeared. This can be explained by the sun moving the 180° the 11 days before the equinox April 11 and earth shifting the 22° in forward precession to the 800 BC orientation to keep earth in the same season making these four stars mark the four seasons. A second miracle on the same day of the year, several years later - Yao's unicorn in the sky in his seventh year, and earth would flow out of the reverse orbit and earth reorient and continue as if nothing had happened. Joshua's long day perhaps February 25 1238 BC, as described in king Wan's dream, may have likewise resulted in a reverse orbit. Thus "about a whole day" = 12 hours. See Joshua's long day