Skywrite

2nd-Level Transmutation (Ritual)
Casting Time: 1 action
Range: Sight
Components: VS
Duration: (C) 1 hour

As in Xanathar's Guide to Everything with the following added:

At Higher Levels. When you cast this spell using a spell slot of 4th or 5th level, the spell lasts up to 8 hours. If you cast this spell using a spell slot of 6th level or higher, the spell lasts up to 24 hours. Using a spell slot of 5th level or higher grants you a duration that does not require concentration.

Source: XGE 165

Changelog

Added upcasting option.