f;><code class=language-ruby data-lang=ruby><span>$ cat epochs.txt
</span><span>@</span><span style=color:#b3933a;>0000000000
</span><span>@</span><span style=color:#b3933a;>1234567890
</span><span>@</span><span style=color:#b3933a;>2222222222
</span><span>
</span><span style=color:#7f8989;># recall that the -u option gives you UTC
</span><span>$ date </span><span style=color:#72ab00;>-</span><span>u </span><span style=color:#72ab00;>-</span><span>f epochs.txt </span><span style=color:#72ab00;>+</span><span