Best practice for Datefield?

Hello short question: Whats the best and comfortable way to work with Date fields? Set datefield in Mysql DB or Timestamp? Or should i use another field? Unixtime is nice for knowing when a tablerow was inserte or not?

Why I‘m questioning is because here in Europe we use different timezone and we use DDMMYYYY instead other format in US or similar.

And later for working with Jquery/Bootstrap Datepicker how to use it properly for not converting these Dateformat forward and backwards again to strugge with it?

And bonus question: How to work with Timezone if a portal is working in multiple countries with different timezones?