1) To paraphrase, in part, Rabbi Matis Weinberg (Patterns in Time), to the non-Jewish world, time is a linear flow without relation to anything external. No instant of time is truly connected to any other, or every instant of time is the same as any other instant of time. This is the position of Sir Isaac Newton in his Principia Mathematica: “Absolute, true, and mathematical time, of itself and from its own nature, flows equably without relation to any thing external …”
3) Roman emperors had the power to interfere as they pleased with the calendar, shortening or lengthening by days the duration of the year. Since time, in Christianity and Islam, is not related to anything external, the early Christians arbitrarily changed the Sabbath to Sunday, whereas Islam, if it may be said to have a Sabbath, arbitrarily changed it to Friday.
4) To those who see time as unrelated points on a line, the calendar is a convenience, not a reality. Commemoration is an arbitrary mental review of political or romantic or seasonal association. Although President George Washington’s actual birthday was February 22, it so happens that in 1971 the federal holiday was shifted to the third Monday in February. Nations move about their holidays at will.
5) “But the Torah,” says Weinberg, “envisions time as our contact with reality, as the definer of our environment and our spiritual attitudes and moods, the basis of events which comprise our history and our individual lives. Commemoration is more than memory: it is a temporal re-living of those aspects in time which created events, dealing anew the associate moods and sensation. From the Torah’s viewpoint, the calendar is the precise opposite of arbitrary, for it represents the deepest manifestation of kedushat Yisrael.”
6) The Torah Jew knows that God is the Master of time, just as he is the Master of war (Hashem ish milchama, Exodus 15:3). However, through prayer and mitzvot, He has given man the opportunity to alter the external world which flows through time. As it says in Pirkei Avoth 2:4): “Do God’s Will as you would do your own will, so that He may do your will as if it were His.”