+item;
we now calculate the time remaining in the delta (if any), and sleep that long, instead of sleeping for the delta;
conversion of seconds to milliseconds (for the delta) now happens at arg-parsing;
oops, we need to fix the way the default value gets set here:
 - since we now convert to ms while parsing, the intended default of 60 s is now actually 60 ms, which is not what we want;
 - we fix this by specifying 60000 ms as the default, but providing "60" as the description, so as not to confuse the user;