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Upload DATA at HJD and UT or UTC ? with MUNIWIN AAVSO Extended format

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Bernhard's picture
Upload DATA at HJD and UT or UTC ? with MUNIWIN AAVSO Extended format

Hello togehter,

My timezone from Europe/Vienna is at

winter time    MEZ: UTC + 1,

summer time:  MEZS: UTC + 2

Uploading data must be in UT or UTC ? The Light curve generator is showing data points at UTC, while...

  • DATE: The format of the date used in the report. Times are midpoint of the observation. Convert all times from UT to one of the following formats:
    • JD: Julian Day (Ex: 2454101.7563)
    • HJD: Heliocentric Julian Day
    • EXCEL: the format created by Excel's NOW() function (Ex: 12/31/2007 12:59:59 a.m )

Wikipedia is saying the difference between UT and UTC should be less than 9 seconds..?

My question is: Does WEBObs needs the HJD in UTC?

So I need to correct my DSLR measurements in:

summertime: MEZS - 2 = UTC    correction: 2h to the past

wintertime: MEZ - 1 = UTC     correction: 1h to the past

before uploading...


regards Bernhard


Eric Dose
Eric Dose's picture

There is no single UT. It can refer to any one of several timescales. "UT" should be avoided in the future as ambiguous. (And yes, AAVSO should purge "UT" from all its web pages in favor of "UTC".)

Use UTC (or HJD). UTC is very well defined, a de facto standard, and will never differ from UT1 by more than 0.9 (not 9) seconds.

Bernhard's picture
Thank you, Eric.

Thank you, Eric.

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