Handling a 14-Hour Timezone Mismatch in NASA's APOD API

While building a client-side calendar app using NASA's Astronomy Picture of the Day (APOD) API, I encountered a common but tricky challenge in global web development: timezone inconsistency. My app was designed to fetch and display the daily space image. Everything worked perfectly during my local development hours in Korea (KST). However, I started seeing undefined errors and broken UI elements specifically during the Korean morning hours. The Problem: KST vs. EST After some debugging, I realized the root cause was the time difference. Client (Me): Korea Standard Time (KST, UTC+9) API Server (NASA): Eastern Standard Time (EST, UTC-5) Korea is 14 hours ahead of the US East Coast. When it was, for example, 10:00 AM on March 29th in Korea, it was still 8:00 PM on March 28th at NASA's headquarters. My initial code was request-driven by the client's local date. When the app requested data for "today" (March 29th KST), the NASA server responded that the data for that date did not exist yet.