If you travel by train to Zaragoza from either Barcelona (high speed train; in 1,5 hrs) or Madrid (idem; 1.20hrs) you have to take care to arrive before 15.40 hrs when the last train of the day leaves Zaragoza for Jaca; arriving shortly after 19hrs.
You can also fly to Bilbao and then take a direct bus to Zaragoza (several services per day; that take aprox 4 hrs).
There is only one train connection per day between Bilbao- Zaragoza andt it arrives after 19 hrs in Zaragoza, so you will need an extra night there if you want to continue to Jaca by train.
From Pau in France, you can continue by either bus or train to Bedous; then have to change to a bus that takes you to Canfranc and then again chose between bus or train to reach Jaca. It takes about 4,5-5 hrs to cover this route.
Opening hours: Mon-Fri 9:00am – 6:00pm (CET)
Opening hours: Mon-Fri 9:00am – 6:00pm (CET)