The difference between calendar days, business days and working days It raises questions when calculating holiday entitlement, leave, notice periods, administrative procedures and internal dates.
The problem arises when a document specifies a number of days but does not explain how they should be counted. Are weekends included? What about public holidays? Does the period start on that very day or the following day?
There is no single answer that applies in all cases. First, you need to identify the type of deadline and then check the relevant regulation, agreement, contract or timetable.
The difference between calendar days, business days and working days
Although these terms are frequently used, they do not mean the same thing:
- Calendar days: They are all the days of the calendar.
- Working days: These are the days during which certain procedures may be carried out or certain time limits calculated.
- Weekdays: These are the days on which a person is required to work according to their rota or shift.
The main difference lies in the days that are included and the context in which each concept is applied.
What are calendar days?
The calendar days These are all the days of the year, including Saturdays, Sundays and public holidays.
A period of seven calendar days comprises seven consecutive days. If that period includes a Sunday or a public holiday, these are also counted.
Example: If a period begins on a Monday and spans seven calendar days, the seven subsequent days are counted consecutively, including Saturday and Sunday. The exact start date will depend on the provisions of the relevant regulation or document.
In the workplace, the Workers’ Statute expressly refers to calendar days in certain cases. For example, it stipulates a minimum duration of thirty calendar days for annual leave and fifteen calendar days for leave to marry or register a civil partnership.
What are working days?
The working days These are the days considered valid for the calculation of a specific time limit. This concept is particularly relevant in administrative proceedings.
Under Article 30 of Law 39/2015, where an administrative time limit is expressed in days and the law does not specify otherwise, it is understood to refer to working days. In such cases, the following are excluded:
- On Saturdays.
- On Sundays.
- Public holidays.
In these proceedings, the time limit usually begins on the day following service or publication. If the last day falls on a non-working day, it is extended to the next working day.
This rule applies to administrative procedures. It should not be automatically applied to holidays, leave, contracts or private employment-related communications.
What are working days?
The working days These are the hours during which a person is scheduled to work, according to their timetable, working day or shift.
That is why one day may be a working day for one person and a day off for another. For example:
- A person works from Monday to Friday.
- Another one works from Tuesday to Saturday.
- A third employee works rotating shifts.
Saturday will be a working day for the second person, but not necessarily for the first. In teams with different shifts, centres or timetables, it is not enough simply to check the general timetable.
Comparison table
| Concept | What’s included | Where it is usually used |
|---|---|---|
| Calendar days | Every day of the year, including Saturdays, Sundays and public holidays | Holidays, leave or deadlines where expressly stated |
| Working days | The days counted towards a specific time limit; in administrative proceedings, Saturdays, Sundays and public holidays are usually excluded | Notifications, appeals and administrative procedures |
| Weekdays | A person’s working days according to their timetable or shift | Working hours, planning, holidays, leave and absences |
How to work out which days to count
Before calculating a date, it is advisable to follow these steps:
- Identify what type of deadline it is.
- Check whether the text refers to calendar days, business days or working days.
- Check the relevant regulation, agreement or contract.
- Please confirm the date from which the calculation begins.
- Please check the relevant public holidays.
- Check the person’s timetable or rota, if it is a weekday.
- Record the criteria used.
It is not enough simply to enter a number of days into the calendar. The result may vary depending on the starting point, public holidays and the method of calculation.
How to count the days during the holidays
The Workers’ Statute stipulates that annual leave must not be for a period of fewer than thirty calendar days. However, collective agreements and individual contracts may specify the arrangements for taking leave and set a benchmark in working days that meets or exceeds this minimum.
Therefore, before deducting holiday pay, the company must check:
- What the collective agreement stipulates.
- Whether the balance is expressed in calendar days or working days.
- Which calendar has been assigned to the employee?.
- How weekends and public holidays affect the requested period.
- Whether there are shifts or rotating breaks.
Combining a balance calculated in working days with requests calculated in calendar days can lead to significant errors.
How are days of leave counted?
Not all types of leave are calculated in the same way. The Workers“ Statute expressly states that leave for marriage or the registration of a civil partnership is fifteen calendar days. For other types of leave, it uses only the word ”days’.
In such cases, the company should review the current wording of the regulation, the collective agreement and the applicable interpretation. It is not advisable to assume that all leave automatically includes weekends and public holidays.
It is also necessary to check when the event giving rise to the leave occurred and what was the first day on which the person was due to work.
How administrative time limits are calculated
In administrative proceedings, if a notice specifies a time limit in days without stating that these are calendar days, the general rule under Law 39/2015 is to treat them as working days.
In addition:
- The period generally begins on the day following notification or publication.
- Saturdays, Sundays and public holidays are excluded.
- If the final day is a non-working day, the due date is extended to the next working day.
- If the deadline is expressed in calendar days, this must be stated.
Lists of non-working days may vary depending on the region and the relevant public authority, so you should also check the relevant official calendar.
Notice periods and employment notifications
In the case of voluntary resignation, a change to a contract or other employment-related notification, the rule regarding administrative working days should not be applied automatically.
To calculate the notice period correctly, you need to check:
- The drafting of the collective agreement.
- The employment contract.
- The date on which the communication was received.
- Just the sort of day.
- The last scheduled working day.
If the document does not specify how the days are counted, it is advisable to check this before finalising the date.
Common mistakes when counting days
Many errors do not stem from the calculation itself, but from having chosen the wrong criterion.
- To think that calendar days do not include Sundays.
- Using “skilled” and “working” as if they were synonyms.
- Apply the administrative rules to any employment contract.
- Count all permissions in the same way.
- Do not check the date on which the period begins.
- Forget about regional or local public holidays.
- Failing to take the employee’s shift into account.
- Do not keep a record of the criteria used to approve an application.
How to avoid mistakes when taking holidays and leave
To minimise uncertainty, the company should set out clear criteria and keep its timetables up to date.
- Please specify whether the balances are expressed in calendar days or working days.
- Set up calendars by centre, team or individual.
- Record national, regional and local public holidays.
- Check the agreement before setting up permissions.
- Centralise requests and approvals.
- Keep a record of changes.
- Explain to staff how each type of absence is calculated.
An application should not depend on manual calculations that vary depending on who reviews it.
How to manage days and requests with Staffy
Staffy helps to centralise requests, holiday entitlements and absences so that HR, managers and staff can work with clearer information.
With the request manager, you can:
- Centralise holiday requests, leave requests and other requests.
- Check timetables and absences.
- Check the status of each request.
- Keep a record of requests and replies.
This means that requests are not scattered across emails, messages or informal conversations.
Frequently Asked Questions
Do calendar days include Saturdays, Sundays and public holidays?
Yes. Calendar days include every day of the year, without excluding weekends or public holidays.
Are Saturdays working days?
Within the time limits set out in Law 39/2015, Saturdays are excluded from the calculation. In other areas, the specific regulation must be checked, as this administrative rule does not automatically apply to all time limits.
What is the difference between a business day and a working day?
A working day is used to determine whether a time limit can be calculated or whether a procedure can be carried out. A working day is a day on which a person is scheduled to work according to their timetable or shift.
Are holidays counted in calendar days or working days?
The Workers’ Statute sets a minimum of thirty calendar days, but a collective agreement or contract may specify a system based on working days that meets or exceeds that minimum.
Are days off always counted in working days?
A one-size-fits-all rule should not be applied to all types of leave. It is necessary to examine the specific type of leave, the current wording of the Workers’ Statute, the collective agreement and the circumstances of the case.
When does a time limit start to run?
It depends on the applicable legislation. In administrative proceedings governed by Law 39/2015, time limits expressed in days generally begin on the day following notification or publication.
Notice: This content relates primarily to the Spanish legal framework and is provided for information purposes only. It is not a substitute for employment or legal advice. Before calculating holiday entitlement, leave, notice periods or time limits, check the relevant legislation, collective agreement, contract and calendar.
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