Do you get the extra attack from a Haste spell you cast on yourself with 1 round duration?

A rogue PC in my campaign has just picked up the Trapsmith prestige class and gained spellcasting this way. He picked Haste as one of his first spells. Now I wonder: His current caster level is 1. If he casts haste, how long does it last? Only the round he casts the spell? Then he would only benefit from increased speed (+30 feet or double, whichever is lower) and +1 dodge to Reflex and AC until his next turn. Or could he transfer the benefit to the next round, if he takes his move action first and then casts the spell with the standard action?