My dad will be in rehab for 100 days soon. If I put him in the VA for 30 days, when will his 100 days start back up?

He had a broken femur in Sept but now dementia has also come a big problem. We are on the waiting list for the Menlo Park, NJ VA home but running out of time of the 100 days. We have the option of putting him in a VA hospital sub acute facility but that is only 30 days. When can the 100 days start back up? Thank you