Add another option for auto-expire length

Although it would probably be better to have a separate number drop down and unit drop down (i.e. units are days, weeks, months, years and numbers are 1-31), for now, it would be great if more options were included in the following line of code:

$period = drupal_map_assoc(array(86400, 172800, 259200, 604800, 1209600, 2419200, 2592000, 5184000, 7776000, 31449600), 'format_interval');

I added just that last number to allow for 52 weeks. I imagine it wouldn't be too uncommon to track points on an annual basis. My site will be giving annual awards.

Would like to see this added just so I don't have to hack the module at each upgrade.

Thanks.