What is the maximum duration for an area effect cloud?

This command:

 /summon minecraft:area_effect_cloud ~ ~ ~ {Duration:630720000}

... summons an invisible marker entity that (supposedly) won't disappear for a year (real life time.) I want to know if this will exceed the maximum Duration that an area_effect_cloud can last (if any).

The Duration tag of an AEC is an Integer, that means that its maximum value is 2147483647.

Everything above will wrap around, so for example Duration:4294967297 becomes Duration:1. You can test this by setting it to 2147483647 or 2147483648 and then checking its NBT data with /data get entity @e[type=area_effect_cloud,sort=nearest,limit=1] Duration.