22 lines
954 B
JavaScript
22 lines
954 B
JavaScript
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var MILLISECONDS_IN_MINUTE = 60000
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/**
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* Google Chrome as of 67.0.3396.87 introduced timezones with offset that includes seconds.
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* They usually appear for dates that denote time before the timezones were introduced
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* (e.g. for 'Europe/Prague' timezone the offset is GMT+00:57:44 before 1 October 1891
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* and GMT+01:00:00 after that date)
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*
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* Date#getTimezoneOffset returns the offset in minutes and would return 57 for the example above,
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* which would lead to incorrect calculations.
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*
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* This function returns the timezone offset in milliseconds that takes seconds in account.
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*/
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module.exports = function getTimezoneOffsetInMilliseconds (dirtyDate) {
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var date = new Date(dirtyDate.getTime())
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var baseTimezoneOffset = date.getTimezoneOffset()
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date.setSeconds(0, 0)
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var millisecondsPartOfTimezoneOffset = date.getTime() % MILLISECONDS_IN_MINUTE
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return baseTimezoneOffset * MILLISECONDS_IN_MINUTE + millisecondsPartOfTimezoneOffset
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}
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