Xel of Unknown loved Elemental Weapon but found the spell very lacking, so they worked to upgrade the thing in a minor way. It now lasts a full day. Also it can be used on magical weapons.

A weapon you touch becomes an elemental weapon.  Choose one of the following damage types: acid, cold, fire, lightning, or thunder. For the duration, the weapon has a +1 bonus to attack rolls and deals an extra 1d4 damage of the chosen type when it hits.

At Higher Levels. When you cast this spell using a spell slot of 5th or 6th level, the bonus to attack rolls increases to +2 and the extra damage increases to 2d4. When you use a spell slot of 7th level or higher, the bonus increases to +3 and the extra damage increases to 3d4.