import datetime
ts = 1000000000
dt = datetime.datetime.utcfromtimestamp(ts)
print(dt) # 2001-09-09 01:46:40const ts = 1000000000;
const date = new Date(ts * 1000);
console.log(date.toISOString());
// 2001-09-09T01:46:40.000Zimport java.time.Instant;
import java.time.ZoneOffset;
long ts = 1000000000L;
Instant instant = Instant.ofEpochSecond(ts);
System.out.println(instant);
// 2001-09-09T01:46:40.000Z