Circadian is the fourth studio album by Canadian instrumental progressive metal band Intervals.

Distorted Sound scored the album 9 out of 10 and said: "Perhaps most impressively, Circadian never falls into the trap many guitar-driven instrumentals are prone to – overemphasis on technicality without purpose, outweighing what's actually enjoyable to listen to.

The intricacy of the music only exists to benefit the overall flow of the whole record and Circadian's sub-40-minute running time passes by like a cool breeze.

However, the unending assault of nitro-fuelled guitar runs and booming djent sections don't leave enough room to reflect on any of the more gorgeous melodies that blister on by.

"[10] Ultimate Guitar rated the album 9 out of 10 and stated, "Aaron displays a huge amount of talent, technical ability, but also taste, and a tendency toward crafting great, catchy melodies, and if you're into instrumental guitar music, you'll definitely want to give Circadian a listen.