Cron jobs in http_poller

Hi,

I'm using http_poller in input and running it via cron job. I have scheduled it for everyday as per my understanding but it is running every 48 hours. Please assist.

Cron job:
cron => "0 5 1-31 * * UTC"

Platform:
Linux

Thanks

Same cron job is running fine on Windows that is everyday.

Any suggestions on this one?