title: Format std::time output
body: <p>I want to display the current time in a certain format. </p>
  
  <p>I am trying to avoid the <a href="https://crates.io/crates/time" rel="noreferrer">time crate</a> since it's flagged as deprecated on its <a href="https://github.com/rust-lang-deprecated/time" rel="noreferrer">the GitHub repo</a>.</p>
  
  <p>I want to use this exact format <code>time::now().strftime("%Y-%m-%d][%H:%M:%S").unwrap()</code> using <code>std::time</code>, but it doesn't seems to have a <code>strftime</code>.</p>