This article is confusing about a "day" on Venus.
It says that a "day" on Venus "last 243 Earth days". But, that is a "
sidereal day", which is the time it takes for an observer on Venus (if there was one and he/she could see through the thick atmosphere) to see the same
star (other than the sun) at the same point in the sky after one rotation.
That is different than the time that it takes Venus to rotate to the point where
the sun is in the same point in the sky after a rotation, because Venus is orbiting the sun in a (nearly) circular path, and that alone changes the angle of the sun after one
sidereal rotation. Because Venus rotates "retrograde", its rotation brings the sun to "high noon" faster than the sidereal day length would indicate. So a
solar day on Venus is only 116.75 Earth days.
That means that the period of light on Venus is about 58 Earth days long, followed by a similar period of darkness. And, those are what we think of as "day" and "night".
See
https://www.universetoday.com/14282/how-long-is-a-day-on-venus/ .