I'll just do recent ones.

VII would take a long time. I'm fairly certain it states that at least two weeks go by within relatively short playing time. Notably the beginning of disc two, and all of disc three.
Add to that the party sleeping (not including tents etc) on several occasions. The time it would take to travel, fight, heal etc. I reckon your talking at least a month or two.

VIII I would suspect would last longer. Purely because of the plot's rythm. It wouldn't make sense for things to happen quickly, and there was a lot of drifting and exploring done on the Garden.

IX was based around events that were happening fairly quickly, it was basically retaliations between areas, with you going along with the flow. I'd say that's fairly short. Less than a month.

X I'm not sure. It had a realtime feel because of the way you progressed, but it couldn't have been that fast. I really don't know.