On this day, morning prayer was at 10 to six AM and evening prayer was at 10 to six PM... This would imply that day and night would be equal today, yes...well, thousands of years of watching this phenomena shouldn't be too far off.
Every religion observes natural events such as solar and lunar movements for various events, observances, holidays, etc. In Islam, observing the moon to figure out when holidays begin (at sunset or at the new moon, etc.) and observe the solar movements for the 5 daily prayers. In Judaism, same as Islam except for the 5 daily prayers. In Christianity, one particular solar and lunar event is most significant. The equation for Easter is as such: the First Sunday AFTER the First Full Moon AFTER the Spring Equinox. These are just book religions, the list goes on, but in one of my classes yesterday, my kids figured out that solar and lunar observances are nothing special to any one religion. :) It's a human thing to watch celestial bodies we do not fully understand...