zone meridian

zone meridian

[′zōn mə′rid·ē·ən]
(astronomy)
The meridian used for reckoning zone time; this is generally the nearest meridian whose longitude is exactly divisible by 15°.
References in periodicals archive ?
Adjusting for the difference between your longitude and your local time zone meridian, converted into minutes, will give you a more accurate time.
For one thing, daylight-saving time pushes solar noon an hour past clock noon, and the fact that Eugene is west of the Pacific Time Zone meridian adds about another 15 minutes.
To make sure you don't do it backward, use this formula: Standard time = LMT + Correction, where the correction is positive west of your time zone meridian, negative east of it.
Otherwise, to get standard time add four minutes to times obtained from the chart for each degree of longitude that you are west of your time zone meridian.
Also, insert your local correction and, when necessary, add one hour for Daylight Saving Time; to get your standard time subtract 4 minutes for each degree you are east of your time zone meridian or add 4 minutes for each degree you are west of it.
Now, a lot goes into making it this way, such as the shape of the Earth's orbit and the tilt of its axis, time zone meridians and the amount of potatoes consumed on Thanksgiving (just kidding).