Do the different time zones and the international date line affect the global observance of the weekly Sabbath?
It is a fact that people observe the weekly Sabbath at different times around the globe. While someone in Jerusalem may be observing the Sabbath starting at 6:00 p.m., someone living in New York City will begin their Sabbath observance seven hours later. Does this somehow make void or affect the true observance of the Sabbath in anyway?
We must remember that the Creator knew what He was doing when He created a spherical planet that would rotate on its axis, exposing certain parts of the Earth to sunlight at different times. This would naturally create a time difference, based on the rotation of the planet.
God created the 24-hour day at Creation (Genesis 1:1–5). Therefore, He would have been fully aware that our days and months would be based on the solar and lunar cycles, in relation to the earth’s rotation. For example, if Paul was doing missionary work in Rome at the same time that Thomas was doing missionary work in India, would they observe the Sabbath hours at the exact same time? Well, yes, and no—since there’s a three-and-a-half-hour difference between when the sun goes down in India and when the sun sets in Rome. Thomas would start observing the Sabbath three-and-a-half hours before Paul, based on the setting of the sun. However, they would indeed share 21 hours of Sabbath observance at the same time.
The weekly cycle has never changed since the beginning of time. There have always been seven literal 24-hour days in a week. The start and finish of those individual days differs in different regions of the planet, based on the rotation cycle, but God expects us to observe the Sabbath according to His command.
A day starts at sundown (Genesis 1:5; Leviticus 23:32); so therefore, every biblical seventh-day (Saturday) should be honored as the Lord’s Sabbath according to the daylight patterns in your geographical region. While someone may have a seven-hour advance on Sabbath-keeping in Jerusalem compared to New York City, they are still observing the Sabbath of the Lord according to the counsel given in the Holy Scriptures.