// Created on savesnippets.com · https://savesnippets.com/Lfc2FDSS5iZHnv
export function isWithinInterval(date: Date, start: Date, end: Date): boolean {
  const t = date.getTime();
  const lo = Math.min(start.getTime(), end.getTime());
  const hi = Math.max(start.getTime(), end.getTime());
  return t >= lo && t <= hi;
}

isWithinInterval(new Date('2025-03-15'), new Date('2025-03-01'), new Date('2025-03-31'));  // true
isWithinInterval(new Date('2025-04-01'), new Date('2025-03-01'), new Date('2025-03-31'));  // false