180+10 does not mean you can make dining reservations 190 days ahead of time. It means, if you are staying at a WDW resort or Swan/Dolphin you can start making your reservations for your entire length of stay, up to 10 days, 180 days prior to check-in. So, in essence, yes, if you are staying onsite, you can make all of your dining reservations (for length of stay) at 180 days prior to check-in. If you are staying OFFSITE, you have to get up every day and make the reservations 180 days ahead of time as you don't get length-of-stay advantages by staying offsite.