Why does this echo values in the wrong order?

I’m sure there is a simple reason/answer for this: Why does

echo 'Archive for '. the_time('Y');

give me 2010Archive for? I had expected it would give me
Archive for 2010

As most template tags that start with the_ this one echoes time and not returns it (which template tags that start with get_the_ do).

First the_time() fires and echoes year, then its return (null) gets concatenated and echoed with string.

So:

echo 'Archive for ';
the_time('Y');

Or:

echo 'Archive for ' . get_the_time('Y');