Latitudinal extent refers to the distance measured in degrees north or south of the equator. As one moves from south to north, the duration of day and night varies due to the following factors:

Angle of incidence of sunlight

The angle of incidence of sunlight is determined by the position of the sun in the sky. At the equator, the sun is directly overhead, resulting in almost equal day and night duration throughout the year. However, as we move towards the poles, the angle of incidence decreases, resulting in longer nights and shorter days during the winter months.

Seasonal variations

The tilt of the earth's axis causes seasonal variations in day and night duration. During the summer solstice, the sun is at its highest point in the sky, resulting in longer days and shorter nights. Conversely, during the winter solstice, the sun is at its lowest point in the sky, resulting in longer nights and shorter days.

Polar regions

At the poles, the day and night duration is extreme. During the summer months, the sun never sets, resulting in continuous daylight. Conversely, during the winter months, the sun never rises, resulting in continuous darkness.

Conclusion

In conclusion, latitudinal extent influences the duration of day and night due to the angle of incidence of sunlight, seasonal variations, and the extreme conditions at the poles. As one moves from south to north, the duration of day and night varies, resulting in unique environmental conditions that impact the flora, fauna, and human population of a region.

As we know that our earth has imaginary lines running from west to east which are called latitudes. The 0 degree latitude is called the equator and 90 degrees
(S and N) are poles.The duration of day and night may vary depending upon the value of latitude and sun's position.
The earth's axis is tilted at an angle of 66.5 degrees on the orbital plane. So during revolution of earth around sun the sun rays falls on different latitudes , this is called solar insolation.
The difference in duration of day and time depends on intensity of sunlight. The equator always receives intensive solar rays which makes both day and nights are of equal duration(12hrs each - equinox March 21st September 23rd ).
However as we go higher latitudes solar insolation reduces. Depending on Sun position whether in northern or southern hemisphere the days are either longer or shorter.
When sun is in northern hemisphere it experience longer days at the same time southern hemisphere experience longer nights(summer solstice - June 21st), but when the sun is in southern hemisphere the phenomenon is reversed (winter solstice - December 22nd).