This character is a Other Symbol and is commonly used, that is, in no specific script. The character is also known as clock.
The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. U+1F570 offers a line break opportunity at its position, except in some numeric contexts.
The CLDR project calls this character “mantelpiece clock” for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: clock, mantelpiece, time.
This character is designated as an emoji. It will be rendered as monochrome character on conforming platforms. To enable colorful emoji display, you can combine it with Variation Selector-16: 🕰️ See the Emojipedia for more details on this character’s emoji properties.
The Wikipedia has the following information about this codepoint:
Mantel clocks—or shelf clocks—are relatively small house clocks traditionally placed on the shelf, or mantel, above the fireplace. The form, first developed in France in the 1750s, can be distinguished from earlier chamber clocks of similar size due to a lack of carrying handles.
These clocks are often highly ornate, decorative works. They are most frequently constructed from any combination of ormolu, porcelain, and wood. One of the most common and valued types of mantel clocks are the French Empire-style timepieces.
Simon Willard's shelf clock (half clock, Massachusetts shelf clock) was a relatively economical clock which was produced by the celebrated Simon Willard's Roxbury Street workshop, in Boston, Massachusetts, around the first decades of the 19th century. Right after inventing the banjo clock, Simon Willard brought the design further, designing the similar Massachusetts shelf clock which was related to the traditional bracket clocks. Simon's new creation ran for eight days.