The Sacred Hourglass of Akatosh is a housing item which will allow you to manage the display time in your house - setting IIRC are like sunrise, high noon, sunset, midnight (and I could be wrong about the "names" etc).

I don't have a link for the actual info handy sorry.

Interacting with it will change the time of day in your house between several presets (there may be some restrictions in a few houses, like the Grand Psijic Villa):

• Inactive (time flows as normal)
• Sunrise
• Morning
• Midday
• Afternoon
• Sunset
• Midnight

Because it is a Collectible Furnishing, you can place only one hourglass in each house. To get it, you need to own the Soulfire Dragon Illusion and the three hourglass fragments from the Impresario, that will be available during the following events:

• First fragment will be available starting with the Witches Festival 2022.
• Second fragment will be available starting with the Dark Heart of Skyrim Celebration 2022.
• Third and final fragment will be available during the New Life Festival 2022.

Just a heads up, all Soulfire Dragon Illusion fragments and its morph fragments (Skin, Mount, Costume and Furnishing) will be retired in 2023, so New Life Festival 2022 will be your last chance to get these.