Function dateTimeStringTrunc

dateTimeStringTrunc(
    isoString: string,
    precision: DateTimePrecision,
    roundingDirection?: DateRoundingDirection,
): string
Performs a date trunc operation on a datetime string (ISO). Ignores timezones.
Parameters
- isoString: string
  The datetime string (ISO) to truncate.
- precision: DateTimePrecision
  The precision of the truncation.
- roundingDirection: DateRoundingDirection = "down"
Returns string