src/utils/time.js

function parseDateInput(raw) {
  if (!raw) {
    return null;
  }

  const date = new Date(raw);
  if (Number.isNaN(date.getTime())) {
    return null;
  }
  return date;
}

function toIsoString(value) {
  if (!value) {
    return null;
  }
  const date = value instanceof Date ? value : new Date(value);
  if (Number.isNaN(date.getTime())) {
    return null;
  }
  return date.toISOString();
}

module.exports = {
  parseDateInput,
  toIsoString,
};