method Temporal.PlainDateTime.prototype.round
PlainDateTime.prototype.round(roundTo: RoundTo<"day"
| "hour"
| "minute"
| "second"
| "millisecond"
| "microsecond"
| "nanosecond">): Temporal.PlainDateTime
roundTo: RoundTo<"day"
| "hour"
| "minute"
| "second"
| "millisecond"
| "microsecond"
| "nanosecond">