Business Hours Calculator

Business hours count weekdays Monday through Friday only, multiplied by your workday length with a default of 9:00 AM to 5:00 PM Eastern. Weekends Saturday and Sunday are excluded entirely from the total, so a Monday-to-Sunday span of seven calendar days yields exactly five weekdays times eight hours equals forty business hours. Set your own workday start and end in HH:MM 24-hour format to match night shifts, half-days, or flexible schedules common across USA startups and remote teams.

How the math works for USA payroll: The calculator normalizes both dates to midnight local time, walks each calendar day inclusive, keeps days where getDay returns 1 through 5, and multiplies the weekday count by dayHours derived from workEnd minus workStart. For example September 1 to September 7 2026 spans five weekdays at eight hours, producing 40.0 hours, five weekdays, eight hours per day, and seven calendar days spanned. Partial days count as full weekdays, which matches quoting and SLA conventions where any workday touched counts fully toward capacity planning.

USA workweek norms and overtime: The standard USA full-time week is forty hours across five eight-hour days under the Fair Labor Standards Act, with overtime after forty for non-exempt staff. Use 9:00 to 17:00 for office, 8:00 to 16:30 with lunch for trades, or 10:00 to 18:00 for West Coast tech. If your shop runs four tens, set 08:00 to 18:00 and interpret weekdays as ten-hour shifts. For 24/7 support, run the same dates twice with day and night windows and add them.

Holidays, PTO, and partial days: Federal holidays like July 4th, Thanksgiving Thursday, and Christmas are not auto-excluded because observance varies by state and employer in Texas versus New York. Subtract holidays manually by reducing weekday counts or splitting ranges around the holiday. Each weekday counts at full length, so a half-day Friday still counts eight hours unless you split the range into two runs with different windows. For hourly precision within a single day, pair this with a time-duration calculator for start-to-end timestamps.

Privacy and accuracy: All date parsing and arithmetic runs locally in your browser with no uploads, no tracking, and no account. Dates use YYYY-MM-DD to avoid MM/DD versus DD/MM ambiguity that causes missed deadlines in USA offices. Invalid ranges where end precedes start return a clear error instead of negative hours. Midnight normalization avoids daylight-saving edge shifts that plague March and November spans across Eastern, Central, Mountain, and Pacific zones.

Limits and next steps: This tool excludes weekends only and assumes uniform workdays across the span. It does not handle rotating shifts, lunch deductions, or per-day custom hours. For lunch-unpaid shops, set 09:00 to 17:00 then subtract weekdays times one hour, or set 09:00 to 16:00 directly. For SLA clocks that pause overnight, combine weekday totals with ticket timestamps. Copy the result line into proposals, Jira, or invoices as proof of capacity.