Q&A

It is 60,000 miles on cars that were built before 1999, '99-up it's 105,000.
So the replacement interval on your car is 105,000 miles or 105 months, whichever comes first, but Subaru suggests to check the condition in every 30,000 miles or 30 months.
The EJ253 SOHC (non turbo!) engine is a free-wheeling, which means there will be no piston to valve contact even if the belt fails. The 2.5 DOHC Turbo is an interference engine.

Zee

I see a recommended replacement at 105,000 miles or 105 months. For severe use, I'd cut that to 90,000 or less. Severe use includes very dusty conditions, very hot or cold operating conditions, pulling a trailer, off-road use, fast driving (not constant highway speeds but lots of acceleration, etc), heavy traffic with slow speeds, long periods of idling, and so forth. The newest types of belt materials and designs can go the 105k miles these days. In the old days the interval was much shorter with lots of failures, sometimes destroying engines. I wouldn't want to go over the 105k mile spec, myself. At that time, I'd recommend replacing the cam seals and crank seal, as well as the coolant pump. At that mileage, it's worn and not reliable. Any coolant leaking onto the t-belt will likely shorten it's life considerably and cause failure.