Calculate Working Hours Between Two Dates in Python

from datetime import datetime, timedelta

def work_hours_between(start: datetime, end: datetime) -> float:
    """Calculate total working hours between two datetimes (Mon-Fri, 09:00-17:00)."""
    def is_workday(d: datetime) -> bool:
        return d.weekday() < 5
    
    total_hours = 0.0
    current = start
    while current.date() <= end.date():
        if is_workday(current):
            day_start = current.replace(hour=9, minute=0, second=0, microsecond=0)
            day_end = current.replace(hour=17, minute=0, second=0, microsecond=0)
            effective_start = max(current, day_start)
            effective_end = min(end, day_end) if current.date() == end.date() else day_end
            if effective_start < effective_end:
                total_hours += (effective_end - effective_start).total_seconds() / 3600
        current += timedelta(days=1)
    return total_hours

if __name__ == "__main__":
    start = datetime(2025, 1, 13, 10, 30)   # Monday
    end = datetime(2025, 1, 17, 14, 15)     # Friday
    print(f"{work_hours_between(start, end):.2f}")