Weekly opening hours are the sum of every open interval
Weekly opening hours are the total length of all the intervals in which a business is actually open from Monday to Sunday. A café that opens for lunch, shuts for the afternoon and reopens for dinner cannot be measured from its first opening to its last closing, because the gap in between is not open time and must be left out.
The example in the calculator above is a restaurant that is closed on Monday, open 11:00 AM – 3:00 PM and 5:00 PM – 10:00 PM from Tuesday to Thursday, open the same lunch hours and 5:00 PM – 2:00 AM on Friday, 12:00 PM – 2:00 AM on Saturday and 12:00 PM – 9:00 PM on Sunday. Adding every interval gives 63 hours a week, which is 37.5% of the 168 hours in a week. Select a day to change its times and the bars and the opening hours notice below update with it.
When a weekly total is worth knowing
Opening hours tell customers when to come, and they also set how much staff time and running cost a business has to cover. The weekly total is a quick figure for several everyday decisions.
- Planning the staff rota: a 63-hour week means 63 hours that need someone on the floor, before opening-up and closing-down time. One person cannot cover that alone, so the total shows how many shifts have to overlap and where.
- Comparing sales per open hour: the same weekly takings spread over 63 hours and over 45 hours are very different results. Dividing weekly sales by weekly opening hours shows whether longer hours actually paid off.
- Listing hours on Google Business Profile: Google asks for a break as two entries on the same day, which is exactly how this calculator takes intervals. The notice it produces can be copied across day by day.
- Checking a change before making it: opening on a closed Monday or dropping late Friday and Saturday service changes the week by a known number of hours. The comparison table below does this for the example restaurant.
- Comparing sites or rotas: two branches with different day patterns can be put side by side using total hours, open days and the average per open day.
How the calculation works
- Choose a status for each day. A day is Closed, Open with times, or 24 hours.
- Enter the intervals. The opening time is when customers can first come in and the closing time is when trading ends. If the place shuts for a break and reopens, add another interval. Up to three intervals fit in one day.
- Turn each interval into minutes. 9:30 AM is 9 × 60 + 30 = 570 minutes and 6:15 PM is 1,095 minutes, so the interval is 1,095 − 570 = 525 minutes = 8 h 45 min.
- Add a day when the closing time is earlier than the opening time. 10:00 PM – 2:00 AM is 120 + 1,440 − 1,320 = 240 minutes = 4 h, and all 4 hours count for the day it opened. A closing time of 12:00 AM is read as midnight at the end of the same day, so 5:00 PM – 12:00 AM is 7 h.
- Add up the days. The intervals of one day give that day’s total and the seven days give the week. The average per open day is the weekly total divided by the number of days on which an interval starts; closed days are not counted.
- Check for gaps in the data. An interval whose opening and closing times are equal, an empty time or an overlap stops the total from being shown and points at the interval to fix.
Break time is the gap on the same day between the end of one interval and the start of the next. If 11:00 AM – 3:00 PM is followed by 5:00 PM – 10:00 PM, the break is 2 hours. It is left out of opening hours and added up separately in the Break time box.
The example restaurant, day by day
| Day | Open intervals | Opening hours | Break time |
|---|---|---|---|
| Mon | Closed | 0 h | — |
| Tue | 11:00 AM – 3:00 PM, 5:00 PM – 10:00 PM | 9 h | 2 h |
| Wed | 11:00 AM – 3:00 PM, 5:00 PM – 10:00 PM | 9 h | 2 h |
| Thu | 11:00 AM – 3:00 PM, 5:00 PM – 10:00 PM | 9 h | 2 h |
| Fri | 11:00 AM – 3:00 PM, 5:00 PM – 2:00 AM | 13 h | 2 h |
| Sat | 12:00 PM – 2:00 AM | 14 h | — |
| Sun | 12:00 PM – 9:00 PM | 9 h | — |
| Total | 6 open days · average 10 h 30 min | 63 h | 8 h |
Friday’s 5:00 PM – 2:00 AM is 9 hours, so with 4 hours at lunch Friday comes to 13 hours. That interval ends at 2:00 AM on Saturday morning, but those hours stay with Friday. Saturday starts afresh at 12:00 PM and runs to 2:00 AM on Sunday for 14 hours. The hatched stretch at the start of the Saturday and Sunday rows on the bars is the time carried over from the night before.
Dividing 63 hours by 6 open days gives an average of 10 h 30 min. The longest day, Saturday at 14 hours, is 5 hours longer than the shortest, which is 9 hours on Tuesday to Thursday and Sunday. Customers need the day-by-day times, not the average.
Late closings and Sunday night
When the closing time is earlier than the opening time, the business is treated as closing the next day. Monday 10:00 PM – 2:00 AM runs from Monday evening until Tuesday morning, and all 4 hours are added to Monday. The total is grouped by the day trading began rather than split at midnight, so a closed Tuesday does not cut Monday’s late service short.
The calculator also checks the early hours of the next day. Monday 10:00 PM – 2:00 AM together with Tuesday 1:00 AM – 5:00 AM overlap for one hour on Tuesday. Tuesday 2:00 AM – 5:00 AM only touches the edge and is not an overlap. A schedule repeats weekly, so Sunday night runs into Monday morning: Sunday 10:00 PM – 2:00 AM and Monday 1:00 AM – 3:00 AM overlap on Monday from 1:00 AM to 2:00 AM.
Overlapping time is never added twice or merged quietly. It is marked in the warning colour on the bars and the two intervals are named. If the place never actually closed in between, enter one longer interval instead.
What changing the hours does to the week
The table changes the example restaurant (63 h a week) one thing at a time. Enter your own version in the calculator to compare in the same way.
| Change | Weekly hours | Difference |
|---|---|---|
| The example as it stands | 63 h | — |
| Tue–Fri open straight through, no afternoon break | 71 h | +8 h |
| Also open on Monday, like Tuesday | 72 h | +9 h |
| Fri and Sat close at 12:00 AM instead of 2:00 AM | 59 h | −4 h |
| Also closed on Sunday | 54 h | −9 h |
Removing the afternoon break adds 8 hours a week, but if few customers come in that gap the extra cost is mostly wages. Cutting four late hours on Friday and Saturday takes off about 6% of opening time; if the takings in those hours were smaller than the staff and energy costs, the business may keep more money by closing earlier.
Writing the opening hours notice
The notice under the calculator puts consecutive days with identical hours on one line. Three or more days appear as a range such as Tue–Thu, two days as Sat & Sun, and days that are not next to each other are listed separately even when their hours match. A break between intervals is added in brackets. A closing time after midnight is shown as the clock time alone, so 5:00 PM – 2:00 AM, and a closing at midnight is shown as 12:00 AM.
- Last orders are a separate line. If the kitchen takes the last order at 8:30 PM and the doors shut at 9:00 PM, enter 9:00 PM as the closing time and add “last orders 8:30 PM” to the notice.
- Prep and cleaning time depend on the purpose. Leave them out of a notice for customers. For a rota or an energy estimate, work them out as an extra interval.
- Holidays go in as special hours. Google Business Profile has a Special hours setting for holidays and other unusual days. Keep the usual weekly schedule and the one-off changes apart.
Rules that can limit opening hours
Most shops and cafés choose their own hours, but some rules are set by law or by the platform where hours are published. The calculator does not check any of them, so compare its result with the ones that apply to you.
- Large shops in England and Wales on Sundays: under Schedule 1 to the Sunday Trading Act 1994, a “large shop” has a relevant floor area exceeding 280 square metres. A large shop may open on a Sunday for any continuous period of six hours beginning no earlier than 10 am and ending no later than 6 pm. The six-hour allowance does not apply when the Sunday is Easter Day, so a large shop may not open at all that day, and large shops may not open on Christmas Day under section 1 of the Christmas Day (Trading) Act 2004. Some shops are exempt from the Sunday limit, including shops in railway stations, petrol filling stations, certain airport shops and pharmacies that sell only medicines. Smaller shops are not covered by the six-hour limit.
- Google Business Profile: a break is entered as two entries for the same day with different times, 24-hour trading is set with “24 hours” for each day, and holidays or special events go under Special hours. The calculator’s weekly schedule and notice follow the same structure.
A large shop that opens 10:00 AM – 8:00 PM from Monday to Saturday (60 h) and 10:00 AM – 4:00 PM on Sunday (6 h, the longest the Sunday rule allows) totals 66 hours over 7 open days, an average of 9 h 26 min. Enter those times and the calculator gives the same figures. Licensing conditions, local planning conditions and tenancy terms may also limit hours and are not covered here.
Common mistakes
- Mixing up AM and PM: 10:00 PM – 2:00 AM is 4 hours, but entered as 10:00 PM – 2:00 PM it becomes 16 hours. If the total looks wrong, check where the bar sits on the day first.
- Treating 12:00 AM and 12:00 PM the wrong way round: 12:00 AM is midnight and 12:00 PM is noon. A closing time of 12:00 AM ends the day at midnight, while 12:00 PM is the middle of the day.
- Writing 8 h 30 min as 8.30 hours: 30 minutes is 0.5 hours, so 8 h 30 min is 8.5 hours. Use the decimal figure shown in the result when copying into a spreadsheet.
- Measuring from first opening to last closing: entering 11:00 AM – 10:00 PM turns 9 hours into 11 and counts the break as open time.
- Entering 24-hour trading as the same time twice: when opening and closing are equal the calculator reports an error because 0 hours and 24 hours cannot be told apart. Choose “24 hours” for that day.
- Putting the last order time in as the closing time: closing is when trading really ends, which is usually later than last orders.
- Overlapping a late finish with early next-day trading: Friday 5:00 PM – 2:00 AM with Saturday 12:00 AM – 9:00 AM overlap on Saturday from 12:00 AM to 2:00 AM. Enter the night as one Friday interval, or start Saturday at 2:00 AM.
Limits
- The calculator works on a normal repeating week. Specific dates, bank holidays and one-off closures are not included.
- Opening hours are not working hours or pay. Breaks for staff, opening-up and closing-down work and the number of people on a shift have to be worked out separately.
- Every day is treated as exactly 24 hours, so the weeks when the clocks change are not adjusted.
- Times are to the minute and a day holds up to three intervals. A business with more separate sessions should combine the closest ones.
- Everything is calculated in this browser and nothing is sent to a server. The schedule is put into the address only when Copy link is selected.
Sources
- 01NIST SP 811, chapter 5: units outside the SITable 6: 1 min = 60 s, 1 h = 60 min, 1 d = 24 h
- 02WHATWG HTML Standard: time inputThe value is a 24-hour time string; the displayed format can follow the device settings
- 03Sunday Trading Act 1994, Schedule 1Large shop: over 280 square metres; six continuous hours between 10 am and 6 pm
- 04Google Business Profile Help: edit your business hoursBreaks as two entries on one day, 24 hours, Special hours for holidays
Frequently asked questions
How is break time left out?
Enter the hours either side of the break as two intervals. With 11:00 AM – 3:00 PM and 5:00 PM – 9:00 PM the day is 8 h, and the 2 hours between 3:00 PM and 5:00 PM are excluded and added up in the Break time box. Up to three intervals fit in a day.
Which day does 10:00 PM – 2:00 AM count toward?
The day it opened. When the closing time is earlier than the opening time, the calculator treats it as closing the next day and adds all 4 hours to the day it started. The board shows the carried-over part as a hatched stretch at the start of the next day's row.
Do I enter 24-hour trading as 12:00 AM – 12:00 AM?
No. Equal opening and closing times are reported as an error because they could mean 0 hours or all day. Choose 24 hours for that day, which counts 24 h from midnight to midnight; seven days of 24 hours make 168 h a week.
How do I enter a closing time at midnight?
Enter 12:00 AM as the closing time. It is read as midnight at the end of that same day, so 5:00 PM – 12:00 AM is 7 h with nothing carried into the next day, and the notice shows it as 5:00 PM – 12:00 AM.
Does it check Sunday night against Monday morning?
Yes. The schedule repeats weekly, so Sunday is followed by the Monday of the same week. Sunday 10:00 PM – 2:00 AM with Monday 1:00 AM – 3:00 AM overlap for the hour from 1:00 AM to 2:00 AM on Monday, and no total is shown until that is fixed.
Are closed days included in the average?
No. Open days are days with an interval that starts that day, and the average is the weekly total divided by that number. 63 h over 6 open days is 10 h 30 min.
How does the notice group days?
Only consecutive days with identical hours are grouped. Three or more days appear as a range such as Tue–Thu, two days as Sat & Sun, and days that are apart are listed separately even if their hours match. A break appears in brackets.
Does it include bank holidays and special dates?
No. It handles a normal repeating week only. Add holiday or one-off changes to the notice by hand, and on Google Business Profile enter them as special hours.