import datetime
date_str = "1991-02-12"
dt = datetime.datetime.strptime(date_str, "%Y-%m-%d")
ts = int(dt.replace(tzinfo=datetime.timezone.utc).timestamp())
print(ts) # 666316800const dateStr = "1991-02-12";
const date = new Date(dateStr + "T00:00:00Z");
const ts = Math.floor(date.getTime() / 1000);
console.log(ts); // 666316800import java.time.LocalDate;
import java.time.ZoneOffset;
String dateStr = "1991-02-12";
LocalDate date = LocalDate.parse(dateStr);
long ts = date.atStartOfDay(ZoneOffset.UTC).toEpochSecond();
System.out.println(ts); // 666316800