Working with (and across) TIme Zones?

Hi I have some questions about working with Time Zones. I’m hoping someone can help and maybe guide me toward some sort of documentation that can help me.

  1. I’m confused about the fact that our current settings have Time Zone set to “Eastern Time” and Daylight Saving set to “No”. However if I use current date and time, it gives me the accurate daylight savings time. For example, I did a test today at 9:30am and the output was 9:30am. However it was technically 9:30am EDT and 8:30am EST. So if daylight savings time was set to “No”, shouldn’t my output have been 8:30am? I guess I just need some clarification as to how those two time zone settings are meant to function.
  1. What are best practices for working with time zones for an app that will be used across multiple time zones? For example, we have a time clock system. If someone needs to edit a time clock, they have to put in a time. We either need them to put the time in as the local time where the employee is located, or as a standard time, such as Eastern Standard time and then use calculations to adjust that on the back end. How do you recommend that this is best handled? Does anyone have any examples e regarding how you've have handled this effectively?