https://fromkk.com/tags/scala/Recent content in Scala on KK's Blog (fromkk)Hugoenbebound@gmail.com (KK)bebound@gmail.com (KK)Sun, 10 Aug 2025 18:44:06 +0800https://fromkk.com/posts/timezone-in-jvm/Sun, 18 Oct 2020 23:49:00 +0800bebound@gmail.com (KK)https://fromkk.com/posts/timezone-in-jvm/<p>I wrote a Scala code to get the current time. However, the output is different on the development server and docker.</p> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-scala" data-lang="scala"><span style="display:flex;"><span><span style="color:#66d9ef">import</span> java.util.Calendar </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span>println<span style="color:#f92672">(</span><span style="color:#a6e22e">Calendar</span><span style="color:#f92672">.</span>getInstance<span style="color:#f92672">().</span>getTime<span style="color:#f92672">)</span> </span></span></code></pre></div><p>On my development server, it outputs <code>Sun Oct 18 18:01:01 CST 2020</code>, but in docker, it print a UTC time.</p> <p>I guess it related to the timezone setting and do a research, here is the result.</p> <h2 id="how-did-jvm-detect-timezone">How Did JVM Detect Timezone</h2> <p>All of the code can be found in this function: <code>private static synchronized TimeZone setDefaultZone()</code></p>