Discord has a feature that will convert a UNIX time stamp to the local time of the user reading the post. For example: 
East Coast USA: Thursday, March 5, 2026 4:00 PM
Nova Scotia: Thursday, March 5, 2026 5:00 PM
West Coast USA: Thursday, March 5, 2026 1:00 PM

You need the UNIX time stamp of the event. The easiest way to get the UNOX time stamp is to use one of many free tools that are available. This is a good one: UNIX Timestamp Converter https://www.unixtimestamp.com

This is how to post the conversion:
<t:1772732214:F>

You can use it inline for example: The event begins at <t:1772732214:F> so don't be late!
Which will look like: The event begins at Thursday, March 5, 2026 4:00 PM so don't be late!