## What changes were proposed in this pull request?
In the PR, I propose to convert time zone string to `TimeZone` by converting it to `ZoneId` which uses `ZoneOffset` internally. The `ZoneOffset` class of JDK 8 has a cache already: http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/share/classes/java/time/ZoneOffset.java#l205 . In this way, there is no need to support cache of time zones in Spark.
The PR removes `computedTimeZones` from `DateTimeUtils`, and uses `ZoneId.of` to convert time zone id string to `ZoneId` and to `TimeZone` at the end.
## How was this patch tested?
The changes were tested by
Closes#23812 from MaxGekk/timezone-cache.
Lead-authored-by: Maxim Gekk <max.gekk@gmail.com>
Co-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
In the PR, I propose to simplify timestamp truncation to quarter of year by using *java.time* API directly. The `LocalDate` instance can be truncation to quarter timestamp via adjusting by chrono field `IsoFields.DAY_OF_QUARTER`.
## How was this patch tested?
This was checked by existing test suite - `DateTimeUtilsSuite`.
Closes#23808 from MaxGekk/date-quarter-of-year.
Authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
Added the following benchmarks:
- Extract components from timestamp like year, month, day and etc.
- Current date and time
- Date arithmetic like date_add, date_sub
- Format dates and timestamps
- Convert timestamps from/to UTC
Closes#23661 from MaxGekk/datetime-benchmark.
Authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Herman van Hovell <hvanhovell@databricks.com>
