You can use the AlarmFormShowing event to modify the alarm dialog before it is shown. The following code snippet demonstrates how you can enable RightToLeft in it:
sender, RadAlarmFormShowingEventArgs e)
RadForm).RightToLeft = System.Windows.Forms.RightToLeft.Yes;
I hope you find this useful.
A bit off-topic, please note that if you would like to continue receiving support from us, you should first answer our questions in the thread titled "RightToLeft EditRecurrenceDialog" that you can find in your Telerik account.
If you have any further questions, feel free to ask.
All the best,
the Telerik team