Linked from
The 40 pages that link to Second, each with the reason it gives.
Metric systemBroader topic: It anchors metric measurements of time and supports derived units.
Day (time unit)Broader topic: A conventional day contains exactly 86,400 seconds.
Newton-secondBroader topic: It supplies the duration factor in the newton-second.
TimeBroader topic: The second is the standard unit used to quantify duration.