You’re familiar with Oracle’s well-known DATE datatype — it stores both date and time, down to the second — easy and simple. But what happens when your application goes global? Suddenly, what was “just a date” becomes a puzzle of offsets, daylight saving shifts, and unexpected conversions. One user’s “midnight” becomes another’s “yesterday,” and before you know it, you’re lost in time.

In this session, we’ll demystify the timezone maze inside the Oracle Database. We’ll take a practical look at the different datatypes — DATE, TIMESTAMP WITH TIME ZONE, and TIMESTAMP WITH LOCAL TIME ZONE — and understand what they really store, when to use which, and what traps to avoid.

We’ll explore how Oracle manages time conversions, how session and database timezones interact, and why “UTC everywhere” isn’t always the magic fix. Expect real-world coding examples, a few “gotcha” moments, and some fun facts about timezones along the way.

This session starts with the concepts and continues with hands-on examples to help you find your way through the timezone maze. By the end, you’ll have a solid strategy for storing and displaying time correctly in multi-timezone applications — and the confidence to keep your data (and your users) perfectly in sync, no matter where in the world they are.

Learning Objectives

* Understand the differences between Oracle’s date and time datatypes (DATE, TIMESTAMP WITH TIME ZONE, and TIMESTAMP WITH LOCAL TIME ZONE).
* Learn how to choose the right datatype and design approach for multi-timezone applications.
* Identify and avoid common pitfalls in timezone handling — from daylight saving quirks to implicit conversions — and apply best practices for reliable, global-ready systems.