In the filter that does the between calculation, SmartDate forces the site's timezone onto whatever value['min'] and value['max'] have even if they aren't in that timezone.
1. Set the site's timezone to PST.
2. Pass a UTC min and max value to the smart date filter.
The filter treats the times as if they are PST rather than UTC.
The problem is here: docroot/modules/contrib/smart_date/src/Plugin/views/filter/Date.php
/**
* Override parent method, which deals with dates as integers.
*/
protected function opBetween($field) {
$timezone = $this->getTimezone();
$granularity = $this->options['value']['granularity'];
// Convert value to DateTimePlus for additional processing.
$a = new DateTimePlus($this->value['min'], new \DateTimeZone($timezone));
$b = new DateTimePlus($this->value['max'], new \DateTimeZone($timezone));
// Granularity requires some conversion.
The between filter should respect the timezone of the min and max values that are passed in.
Needs review
4.0
Code