Workers and employees who work at specified night shift hours are entitled to additional pay known as night shift differential because of the recognized ill effects of working late at night.
Scientists have long studied how disrupting the normal sleep cycle (where people sleep at night and go out during the day) is increasingly linked to serious diseases such as hypertension, heart attack and certain cancers.
The Supreme Court adopted the general view that night work is undesirable both from the management and employee’s points of view for quite some time. One case decided in 1948 cites the following paragraph obtained from Commons & Andrews “Principles of Labor Legislation” in the case of Shell Company of the Philippine Islands:
“The lack of sunlight tends to produce anemia and tuberculosis and to predispose him to other ills. Night work brings increased liability to eyestrain and accident. Serious moral dangers also are likely to result from the necessity of traveling the street alone at night, and from the interference with normal home life.”
In a much later case, the Supreme Court still cited the same quoted paragraph and added that it is only fair that the employee is compensated for the inconvenience of working at night. (Association of International Shipping Lines, Inc. et al vs. United Harbor Pilots’ Association of the Philippines, Inc. GR 172029, Aug. 06, 2008).