Family name จันทร์สมัย (Chansamai 
, จันทร์สมัย , Jansamai ) , all around the world, is a rare cognomen. The surname จันทร์สมัย is habitual in South-eastern Asia, particularly Laos, where it is a rare surname, and Thailand. More frequently, จันทร์สมัย is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Chansamai | Laos, United States, Thailand |
| Jansamai, จันทร์สมัย | Thailand |