The original was in fact in Latin “Baptismus Christi”
If you look at the code for this plugin (modules_v3\calendar_utilities\plugins\yearly_calendar.php) you will see that each of these events has a comment after it with the original Latin name. Before I release updated translation files I will move these to the correct translation comments area so they will be visible to translators when working on them. It might be better to translate from Latin to your own language, rather than Latin > English (my version) > your language.