PublicDashboards: UI improvements (#55130)

* Public dashboard modal UI modifications

public/app/features/dashboard/utils/timeRange.ts

@@ -0,0 +1,22 @@
+import { DateTime, TimeRange } from '@grafana/data';
+import { dateMath, dateTime, isDateTime } from '@grafana/data/src';
+import { TimeModel } from 'app/features/dashboard/state/TimeModel';
+
+export const getTimeRange = (
+  time: { from: DateTime | string; to: DateTime | string },
+  timeModel?: TimeModel
+): TimeRange => {
+  // make copies if they are moment  (do not want to return out internal moment, because they are mutable!)
+  const raw = {
+    from: isDateTime(time.from) ? dateTime(time.from) : time.from,
+    to: isDateTime(time.to) ? dateTime(time.to) : time.to,
+  };
+
+  const timezone = timeModel ? timeModel.getTimezone() : undefined;
+
+  return {
+    from: dateMath.parse(raw.from, false, timezone, timeModel?.fiscalYearStartMonth)!,
+    to: dateMath.parse(raw.to, true, timezone, timeModel?.fiscalYearStartMonth)!,
+    raw: raw,
+  };
+};