MaxGekk edited a comment on issue #26134: [SPARK-29486][SQL] CalendarInterval should have 3 fields: months, days and microseconds URL: https://github.com/apache/spark/pull/26134#issuecomment-542639106 > ... but one day interval may not. As I can understand, new `microseconds` field means actual time duration inside of a day, correct? Back to the example, it means: ``` timestamp'2019-11-03 01:59:59 PST' + interval 2 seconds = timestamp'2019-11-03 01:00:01 PST' ``` and to get `timestamp'2019-11-03 02:00:01 PST'`, we should add another interval: ``` timestamp'2019-11-03 01:59:59 PST' + interval 1 hour 2 seconds = timestamp'2019-11-03 02:00:01 PST' ``` > However, I'd like to know if it's allowed to set timezone to a region name that has undetermined timezone offset. Allowed by whom (SQL standard?)? For example, Java 8 time API allows to get 0, 1 or 2 zone offsets depend on local timestamp, see https://docs.oracle.com/javase/8/docs/api/java/time/zone/ZoneRules.html#getValidOffsets-java.time.LocalDateTime- , see: ``` The mapping from a local date-time to an offset is not straightforward. There are three cases: - Normal, with one valid offset. For the vast majority of the year, the normal case applies, where there is a single valid offset for the local date-time. - Gap, with zero valid offsets. This is when clocks jump forward typically due to the spring daylight savings change from "winter" to "summer". In a gap there are local date-time values with no valid offset. - Overlap, with two valid offsets. This is when clocks are set back typically due to the autumn daylight savings change from "summer" to "winter". In an overlap there are local date-time values with two valid offsets. ``` > If it's not allowed then one day interval is always 24 hours in SQL. The SQL standard defines time zones as TIMEZONE_HOUR:TIMEZONE_MINUTE. Due to this, there is no issue of converting zone id (region name) to offsets.
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