Episervers standard behaviour is to convert DateTime between database, application and editors depending on what time zone the application and editors are in. If would be nice if there would be built in properties (or editor hints) to enable timezone agnostic date+time or date only selections. There's a blog post how to enable this written by Casper Aasgard (https://fellow.aagaardrasmussen.dk/2016/04/23/get-predictive-time-zones-in-datetime-properties/), but this requires you to add custom editors to the site. However, there's no premade extension for date-selection only.
This is probably quite easy to add as a standard functionality to the product, which would save a lot of time and efforts for partners trying to make sites that should have dates that are not tied to Time Zones. (Usually, this is connected with a custom property for selecting the TimeZone).
This is very much needed