How to work with different timezones in Laravel Scheduling

Hey guys!. So I collect time from userA, eg. 06:30PM and timezone is American/Los_Angeles, and save to my database like below.

try {
            $schedules = new Schedule();
            $days = json_encode($data['days']);
            $timezone = auth()->user()->guardian->timezone;

            $time = Carbon::parse($data['time']);
            
            $startDate = $data['startDate'];

            $schedules->days = $days;

            $parsedTime = $time->setTimezone($timezone);

            $schedules->time = $parsedTime->utc();

            $schedules->startDate = $startDate;

            $schedules->save();
            if ($data) {
                return $this->saveSubjectSchedule($data['subject'], $data['topic'], $schedules, $data['kid']);
            }

            return response()->json(['message' => 'Schedule saved successfully', 'success' => true, 'data' => $schedules], 200);
        } catch (\Throwable $th) {
            return response()->json(['error' => 'Failed to save schedule', 'message' => $th->getMessage(), 'success' => false], 500);
        }

And now I want to send email 2 hours before the time the user picked, eg. 06:30PM. This is where I am confused. Do I need to convert to the users timezone before sending the mail, or will the UTC time I saved to DB be enough, since the user picked 06:30PM. COs if I convert to users timezone, it gives me 11:30. Please I really need an explanation and the best way to handle this in Laravel scheduler. Thanks.

This is what I did already for the scheduler -

$adjustedTime = $currentDateTime->addHours(2)->format('H:i'); // Current time plus two hours without seconds

        $assignments = TutorAssignment::whereHas('kidSubjectSchedule.schedule', function ($query) use ($currentDateTime, $adjustedTime) {
            $query->whereDate('startDate', '<=', $currentDateTime->toDateString())
                ->whereTime('time', '=', $adjustedTime)
                ->where(function ($query) use ($currentDateTime) {
                    $dayOfWeek = $currentDateTime->dayOfWeek;
                    $query->whereJsonContains('days', [['value' => $dayOfWeek]]);
                });
        })->with('kidSubjectSchedule')->get();

        return $assignments->pluck('id')->toArray();