Charts: Fix date selection doesn't work anymore (#3913)

Fixes #3908.
Regression from #3627.

Signed-off-by: Florian Hotze <dev@florianhotze.com>

Author: florian-h05

bundles/org.openhab.ui/web/src/components/widgets/chart/chart-mixin.js

@@ -259,7 +259,7 @@ export default {
     setDate(date) {
       const chartType = this.context.component.config.chartType
       const day = dayjs(date)
-      this.endTime = this.addOrSubtractPeriod(chartType ? startOf(chartType) : day, 1)
+      this.endTime = this.addOrSubtractPeriod(chartType ? startOf(chartType, day) : day, 1)
     },
     earlierPeriod() {
       this.endTime = this.addOrSubtractPeriod(this.endTime, -1)