The timezone setting is mandatory and important for specifying an event date time. It is used to determine and calculate for the following:
The date and time of the event. The timezone also can be displayed on the event page so that the participants can know when to join from their own timezone. This timezone information will be important especially when events like online virtual events are joined by people from around the world. For example, Singapore time (UTC+8) 9 AM is equivalent to UK time 1:00 AM on the same day as the UK is at UTC+0.
Timezone is also important in calculating DayLight Saving to accurately display the adjusted time for the particular period of a location accordingly.
According to the timezone, the time in Add To Calendar (such as Outlook calendar, Google calendar, etc.) can be calculated accordingly.
Automated schedule tasks such as Reminder emails can be scheduled based on the time set according to the timezone specified for the event. For example, to send an email 24 hours before the event start date.