Days Between Dates: Holidays, Notice and Deadlines

How many days until vacation? How many working days are needed to calculate the notice period for resignation? How much time do you have to respond to a registered letter? Counting the days between two dates is an operation we perform much more often than we realize, both in private life and in professional and legal contexts. In this guide, we will see how to correctly count days, the difference between calendar days and working days, and the most common practical applications.

Calendar days vs working days: the fundamental difference

First of all, it is essential to understand the difference between these two types of counting, because the result changes dramatically.

Calendar days (or "solar days"): include all days, including Saturdays, Sundays, and holidays. From January 1 to January 31, there are 31 calendar days.

Working days: exclude Saturdays, Sundays, and national holidays. In an average month, there are approximately 20-22 working days, depending on the number of holidays.

Let's make a concrete example. If we need to calculate the days between March 3, 2026 and April 3, 2026:

• Calendar days: 31 days
• Working days (excluding Saturdays, Sundays, and holidays): approximately 23 days

The difference of 8 days can be significant when it comes to notice periods, legal deadlines, or vacation calculations. Our online day calculator lets you get both counts instantly, without the risk of errors.

Public holidays in Italy in 2026

For an accurate calculation of working days, it is essential to know the national holidays. Here is the complete list for 2026:

In addition to these, there is the patron saint's day of the city where you work (for example, June 29 for Rome, December 7 for Milan, September 19 for Naples).

Vacation calculation: how many days you are entitled to

In Italy, the right to vacation is enshrined in the Constitution (Article 36) and the Civil Code. The legal minimum is 4 weeks per year (equal to 20 working days for those who work 5 days a week, or 24 for those who work 6).

National Collective Bargaining Agreements (CCNL) often provide additional days based on seniority:

Practical example: accrued vacation

Marco works in the commerce sector since September 1, 2025. He wants to know how much vacation he has accrued by March 31, 2026. With 26 annual days, he accrues 26 / 12 = 2.17 days per month. In 7 months (September-March) he has accrued: 7 x 2.17 = 15.17 days, rounded to 15 vacation days available.

Notice period for resignation: how to count it

The notice period is the time between the communication of resignation (or dismissal) and the last day of work. The duration varies based on the CCNL, job classification, and seniority.

Example: Commerce CCNL notice period

Important note: the notice period in the commerce sector is counted in calendar days, not working days. If a 4th-level employee with 3 years of seniority submits their resignation on March 15, 2026, their last day of work will be April 4, 2026 (March 15 + 20 calendar days).

Not all CCNLs use calendar days. In the metalworking sector, for example, the notice period is expressed in months and runs from the 1st or 16th of the month. Always check your specific contract.

How to use the calculator for the notice period

With our day calculator, you can instantly verify the exact date of your last working day. Enter the date of resignation submission as the start date and add the number of notice days required by your CCNL.

Legal deadlines: how to count the terms

In Italian law, the calculation of deadlines follows precise rules established by the Civil Code (Article 2963) and the Code of Civil Procedure.

General rules

• The starting day is not counted (dies a quo non computatur): if a 10-day deadline starts on March 5, the first applicable day is March 6 and the deadline is March 15.
• If the deadline falls on a Saturday, Sunday, or holiday, it is extended to the next working day.
• Court recess: procedural deadlines are suspended from August 1 to August 31 (with exceptions).

Example: deadline to appeal a traffic fine

You receive a traffic fine notified on March 10, 2026. You have 60 calendar days to appeal to the Prefect. The count starts from the following day (March 11) and expires on May 9, 2026. If it had fallen on a Saturday or Sunday, the deadline would have shifted to the following Monday.

Example: registered letter with return receipt

You receive a legal registered letter on March 20, 2026 asking you to respond within 15 days. The deadline starts on March 21 and expires on April 4, 2026 (Saturday). Since it falls on a Saturday, the deadline is extended to Monday, April 6, 2026.

Calculating days for severance pay (TFR)

Severance pay (TFR - Trattamento di Fine Rapporto) is also calculated based on actual working days. The formula provides that annual TFR equals the annual salary divided by 13.5. But for periods shorter than a year, the days of actual service must be calculated.

If an employee works from January 15, 2026 to October 10, 2026, our calculator tells you that these are 268 calendar days. For TFR calculation, months are counted as full if at least 15 days were worked in that month.

Practical applications of day calculation

Probation period

The probation period is generally expressed in working days in the CCNL. For example, in the Commerce contract, for a 4th-level employee, the probation period is 60 working days. This corresponds to approximately 3 calendar months, but the precise calculation requires excluding vacation, sick leave, Saturdays, Sundays, and holidays.

Sick leave protection period

The sick leave protection period is the maximum period of illness during which the employee cannot be dismissed. In the Commerce CCNL, it is 180 calendar days in one year. Counting these days correctly is essential for protecting your rights.

Tax deadlines

Tax deadlines are always expressed in calendar days. For example, the 730 tax form must be submitted by September 30, the personal income tax return by November 30. For tax installment payments, subsequent installments after the first are generally due on the last day of each month.

How to count days without errors

The most common mistakes in counting days are:

1. Counting the starting day: in many legal contexts, the first day is not counted.
2. Confusing calendar and working days: always verify whether the deadline is expressed in calendar or working days.
3. Forgetting holidays: besides Saturday and Sunday, remember national holidays and the patron saint's day.
4. Ignoring the extension: if the deadline falls on a holiday, it shifts to the next working day.

To avoid these errors, the safest method is to use our day calculator: enter the two dates and instantly get the exact count in both calendar and working days, with automatic exclusion of Italian holidays.

Days between two dates: the mathematical formula

For those who want to understand how the calculation works "behind the scenes," the formula is relatively simple for calendar days: each date is converted into a sequential number (for example, the number of days from January 1 of year 1) and the subtraction is performed. For working days, you must iterate day by day and exclude non-working ones.

Manual example: days between February 10, 2026 and March 25, 2026.

• Remaining days in February: 28 - 10 = 18 days
• Days in March: 25 days
• Total: 18 + 25 = 43 calendar days

For working days, in this period there are approximately 6 weekends (12 days) plus any holidays, resulting in approximately 30-31 working days. But manual calculation is prone to errors: it is better to rely on the online calculator.

Frequently Asked Questions

Is the starting day counted or not?

It depends on the context. For legal deadlines, the starting day is generally not counted (Article 2963 of the Civil Code). For vacation, the first day of absence is the first vacation day. For the notice period, the day the resignation is submitted is generally not counted. Always verify the specific regulations for your case.

How are notice period days counted in the Commerce CCNL?

In the Commerce CCNL, notice period days are counted in calendar days. The count starts from the day after the electronic submission of resignation. The notice period runs from the 1st or 16th of the month for the Metalworking CCNL, while in Commerce it starts from the actual date.

If a deadline falls on Sunday, when does it expire?

If the final deadline falls on a Sunday or a holiday, it is automatically extended to the next working day. This rule applies to both legal and tax deadlines.

Are sick days counted as calendar or working days?

Sick days for calculating the protection period are generally counted as calendar days, including Saturday and Sunday, unless the CCNL provides otherwise. For calculating the INPS (social security) benefit, however, indemnifiable days are considered, excluding certain holidays.

How are days calculated for mandatory maternity leave?

Mandatory maternity leave lasts 5 months (generally 2 months before and 3 months after delivery, or 1+4 or 0+5 with flexibility). Months are counted as calendar months, not as 30 days each. For the exact date calculation, our day calculator is a practical and immediate tool.

How many working days are there in a year?

In a standard year with 52 weeks, there are 260 weekdays (Monday-Friday). Subtracting the 11-12 national holidays that fall on working days (the number varies from year to year), you get approximately 248-252 working days. In 2026, considering the holidays listed above, the actual working days are approximately 250.