Perú

Business days calculator

Count working days in Perú (no Saturdays, Sundays or holidays)

Between two dates Add business days

Count working days in Perú (no Saturdays, Sundays or holidays)

This month Next 30 days Until year end +10 business days +15 business days +30 business days

7540

business days

From April 4, 1996 to July 23, 2026

We swapped the dates because “to” was earlier than “from”.

Business day 7540
Weekend 3162
Holidays 366

11068 days in the period

11068

Total days

3162

Weekend

366

Holidays

Holidays in the period

Maundy Thursday Thu 4 Apr 1996
Good Friday Fri 5 Apr 1996
Labor Day Wed 1 May 1996
Battle of Arica / Flag Day Fri 7 Jun 1996
Saints Peter and Paul Sat 29 Jun 1996
Air Force Day Tue 23 Jul 1996
Independence Day Sun 28 Jul 1996
Independence Day (2nd) Mon 29 Jul 1996
Battle of Junín Tue 6 Aug 1996
Saint Rose of Lima Fri 30 Aug 1996
Battle of Angamos Tue 8 Oct 1996
All Saints' Day Fri 1 Nov 1996
Immaculate Conception Sun 8 Dec 1996
Battle of Ayacucho Mon 9 Dec 1996
Christmas Wed 25 Dec 1996
New Year's Day Wed 1 Jan 1997
Maundy Thursday Thu 27 Mar 1997
Good Friday Fri 28 Mar 1997
Labor Day Thu 1 May 1997
Battle of Arica / Flag Day Sat 7 Jun 1997
Saints Peter and Paul Sun 29 Jun 1997
Air Force Day Wed 23 Jul 1997
Independence Day Mon 28 Jul 1997
Independence Day (2nd) Tue 29 Jul 1997
Battle of Junín Wed 6 Aug 1997
Saint Rose of Lima Sat 30 Aug 1997
Battle of Angamos Wed 8 Oct 1997
All Saints' Day Sat 1 Nov 1997
Immaculate Conception Mon 8 Dec 1997
Battle of Ayacucho Tue 9 Dec 1997
Christmas Thu 25 Dec 1997
New Year's Day Thu 1 Jan 1998
Maundy Thursday Thu 9 Apr 1998
Good Friday Fri 10 Apr 1998
Labor Day Fri 1 May 1998
Battle of Arica / Flag Day Sun 7 Jun 1998
Saints Peter and Paul Mon 29 Jun 1998
Air Force Day Thu 23 Jul 1998
Independence Day Tue 28 Jul 1998
Independence Day (2nd) Wed 29 Jul 1998
Battle of Junín Thu 6 Aug 1998
Saint Rose of Lima Sun 30 Aug 1998
Battle of Angamos Thu 8 Oct 1998
All Saints' Day Sun 1 Nov 1998
Immaculate Conception Tue 8 Dec 1998
Battle of Ayacucho Wed 9 Dec 1998
Christmas Fri 25 Dec 1998
New Year's Day Fri 1 Jan 1999
Maundy Thursday Thu 1 Apr 1999
Good Friday Fri 2 Apr 1999
Labor Day Sat 1 May 1999
Battle of Arica / Flag Day Mon 7 Jun 1999
Saints Peter and Paul Tue 29 Jun 1999
Air Force Day Fri 23 Jul 1999
Independence Day Wed 28 Jul 1999
Independence Day (2nd) Thu 29 Jul 1999
Battle of Junín Fri 6 Aug 1999
Saint Rose of Lima Mon 30 Aug 1999
Battle of Angamos Fri 8 Oct 1999
All Saints' Day Mon 1 Nov 1999
Immaculate Conception Wed 8 Dec 1999
Battle of Ayacucho Thu 9 Dec 1999
Christmas Sat 25 Dec 1999
New Year's Day Sat 1 Jan 2000
Maundy Thursday Thu 20 Apr 2000
Good Friday Fri 21 Apr 2000
Labor Day Mon 1 May 2000
Battle of Arica / Flag Day Wed 7 Jun 2000
Saints Peter and Paul Thu 29 Jun 2000
Air Force Day Sun 23 Jul 2000
Independence Day Fri 28 Jul 2000
Independence Day (2nd) Sat 29 Jul 2000
Battle of Junín Sun 6 Aug 2000
Saint Rose of Lima Wed 30 Aug 2000
Battle of Angamos Sun 8 Oct 2000
All Saints' Day Wed 1 Nov 2000
Immaculate Conception Fri 8 Dec 2000
Battle of Ayacucho Sat 9 Dec 2000
Christmas Mon 25 Dec 2000
New Year's Day Mon 1 Jan 2001
Maundy Thursday Thu 12 Apr 2001
Good Friday Fri 13 Apr 2001
Labor Day Tue 1 May 2001
Battle of Arica / Flag Day Thu 7 Jun 2001
Saints Peter and Paul Fri 29 Jun 2001
Air Force Day Mon 23 Jul 2001
Independence Day Sat 28 Jul 2001
Independence Day (2nd) Sun 29 Jul 2001
Battle of Junín Mon 6 Aug 2001
Saint Rose of Lima Thu 30 Aug 2001
Battle of Angamos Mon 8 Oct 2001
All Saints' Day Thu 1 Nov 2001
Immaculate Conception Sat 8 Dec 2001
Battle of Ayacucho Sun 9 Dec 2001
Christmas Tue 25 Dec 2001
New Year's Day Tue 1 Jan 2002
Maundy Thursday Thu 28 Mar 2002
Good Friday Fri 29 Mar 2002
Labor Day Wed 1 May 2002
Battle of Arica / Flag Day Fri 7 Jun 2002
Saints Peter and Paul Sat 29 Jun 2002
Air Force Day Tue 23 Jul 2002
Independence Day Sun 28 Jul 2002
Independence Day (2nd) Mon 29 Jul 2002
Battle of Junín Tue 6 Aug 2002
Saint Rose of Lima Fri 30 Aug 2002
Battle of Angamos Tue 8 Oct 2002
All Saints' Day Fri 1 Nov 2002
Immaculate Conception Sun 8 Dec 2002
Battle of Ayacucho Mon 9 Dec 2002
Christmas Wed 25 Dec 2002
New Year's Day Wed 1 Jan 2003
Maundy Thursday Thu 17 Apr 2003
Good Friday Fri 18 Apr 2003
Labor Day Thu 1 May 2003
Battle of Arica / Flag Day Sat 7 Jun 2003
Saints Peter and Paul Sun 29 Jun 2003
Air Force Day Wed 23 Jul 2003
Independence Day Mon 28 Jul 2003
Independence Day (2nd) Tue 29 Jul 2003
Battle of Junín Wed 6 Aug 2003
Saint Rose of Lima Sat 30 Aug 2003
Battle of Angamos Wed 8 Oct 2003
All Saints' Day Sat 1 Nov 2003
Immaculate Conception Mon 8 Dec 2003
Battle of Ayacucho Tue 9 Dec 2003
Christmas Thu 25 Dec 2003
New Year's Day Thu 1 Jan 2004
Maundy Thursday Thu 8 Apr 2004
Good Friday Fri 9 Apr 2004
Labor Day Sat 1 May 2004
Battle of Arica / Flag Day Mon 7 Jun 2004
Saints Peter and Paul Tue 29 Jun 2004
Air Force Day Fri 23 Jul 2004
Independence Day Wed 28 Jul 2004
Independence Day (2nd) Thu 29 Jul 2004
Battle of Junín Fri 6 Aug 2004
Saint Rose of Lima Mon 30 Aug 2004
Battle of Angamos Fri 8 Oct 2004
All Saints' Day Mon 1 Nov 2004
Immaculate Conception Wed 8 Dec 2004
Battle of Ayacucho Thu 9 Dec 2004
Christmas Sat 25 Dec 2004
New Year's Day Sat 1 Jan 2005
Maundy Thursday Thu 24 Mar 2005
Good Friday Fri 25 Mar 2005
Labor Day Sun 1 May 2005
Battle of Arica / Flag Day Tue 7 Jun 2005
Saints Peter and Paul Wed 29 Jun 2005
Air Force Day Sat 23 Jul 2005
Independence Day Thu 28 Jul 2005
Independence Day (2nd) Fri 29 Jul 2005
Battle of Junín Sat 6 Aug 2005
Saint Rose of Lima Tue 30 Aug 2005
Battle of Angamos Sat 8 Oct 2005
All Saints' Day Tue 1 Nov 2005
Immaculate Conception Thu 8 Dec 2005
Battle of Ayacucho Fri 9 Dec 2005
Christmas Sun 25 Dec 2005
New Year's Day Sun 1 Jan 2006
Maundy Thursday Thu 13 Apr 2006
Good Friday Fri 14 Apr 2006
Labor Day Mon 1 May 2006
Battle of Arica / Flag Day Wed 7 Jun 2006
Saints Peter and Paul Thu 29 Jun 2006
Air Force Day Sun 23 Jul 2006
Independence Day Fri 28 Jul 2006
Independence Day (2nd) Sat 29 Jul 2006
Battle of Junín Sun 6 Aug 2006
Saint Rose of Lima Wed 30 Aug 2006
Battle of Angamos Sun 8 Oct 2006
All Saints' Day Wed 1 Nov 2006
Immaculate Conception Fri 8 Dec 2006
Battle of Ayacucho Sat 9 Dec 2006
Christmas Mon 25 Dec 2006
New Year's Day Mon 1 Jan 2007
Maundy Thursday Thu 5 Apr 2007
Good Friday Fri 6 Apr 2007
Labor Day Tue 1 May 2007
Battle of Arica / Flag Day Thu 7 Jun 2007
Saints Peter and Paul Fri 29 Jun 2007
Air Force Day Mon 23 Jul 2007
Independence Day Sat 28 Jul 2007
Independence Day (2nd) Sun 29 Jul 2007
Battle of Junín Mon 6 Aug 2007
Saint Rose of Lima Thu 30 Aug 2007
Battle of Angamos Mon 8 Oct 2007
All Saints' Day Thu 1 Nov 2007
Immaculate Conception Sat 8 Dec 2007
Battle of Ayacucho Sun 9 Dec 2007
Christmas Tue 25 Dec 2007
New Year's Day Tue 1 Jan 2008
Maundy Thursday Thu 20 Mar 2008
Good Friday Fri 21 Mar 2008
Labor Day Thu 1 May 2008
Battle of Arica / Flag Day Sat 7 Jun 2008
Saints Peter and Paul Sun 29 Jun 2008
Air Force Day Wed 23 Jul 2008
Independence Day Mon 28 Jul 2008
Independence Day (2nd) Tue 29 Jul 2008
Battle of Junín Wed 6 Aug 2008
Saint Rose of Lima Sat 30 Aug 2008
Battle of Angamos Wed 8 Oct 2008
All Saints' Day Sat 1 Nov 2008
Immaculate Conception Mon 8 Dec 2008
Battle of Ayacucho Tue 9 Dec 2008
Christmas Thu 25 Dec 2008
New Year's Day Thu 1 Jan 2009
Maundy Thursday Thu 9 Apr 2009
Good Friday Fri 10 Apr 2009
Labor Day Fri 1 May 2009
Battle of Arica / Flag Day Sun 7 Jun 2009
Saints Peter and Paul Mon 29 Jun 2009
Air Force Day Thu 23 Jul 2009
Independence Day Tue 28 Jul 2009
Independence Day (2nd) Wed 29 Jul 2009
Battle of Junín Thu 6 Aug 2009
Saint Rose of Lima Sun 30 Aug 2009
Battle of Angamos Thu 8 Oct 2009
All Saints' Day Sun 1 Nov 2009
Immaculate Conception Tue 8 Dec 2009
Battle of Ayacucho Wed 9 Dec 2009
Christmas Fri 25 Dec 2009
New Year's Day Fri 1 Jan 2010
Maundy Thursday Thu 1 Apr 2010
Good Friday Fri 2 Apr 2010
Labor Day Sat 1 May 2010
Battle of Arica / Flag Day Mon 7 Jun 2010
Saints Peter and Paul Tue 29 Jun 2010
Air Force Day Fri 23 Jul 2010
Independence Day Wed 28 Jul 2010
Independence Day (2nd) Thu 29 Jul 2010
Battle of Junín Fri 6 Aug 2010
Saint Rose of Lima Mon 30 Aug 2010
Battle of Angamos Fri 8 Oct 2010
All Saints' Day Mon 1 Nov 2010
Immaculate Conception Wed 8 Dec 2010
Battle of Ayacucho Thu 9 Dec 2010
Christmas Sat 25 Dec 2010
New Year's Day Sat 1 Jan 2011
Maundy Thursday Thu 21 Apr 2011
Good Friday Fri 22 Apr 2011
Labor Day Sun 1 May 2011
Battle of Arica / Flag Day Tue 7 Jun 2011
Saints Peter and Paul Wed 29 Jun 2011
Air Force Day Sat 23 Jul 2011
Independence Day Thu 28 Jul 2011
Independence Day (2nd) Fri 29 Jul 2011
Battle of Junín Sat 6 Aug 2011
Saint Rose of Lima Tue 30 Aug 2011
Battle of Angamos Sat 8 Oct 2011
All Saints' Day Tue 1 Nov 2011
Immaculate Conception Thu 8 Dec 2011
Battle of Ayacucho Fri 9 Dec 2011
Christmas Sun 25 Dec 2011
New Year's Day Sun 1 Jan 2012
Maundy Thursday Thu 5 Apr 2012
Good Friday Fri 6 Apr 2012
Labor Day Tue 1 May 2012
Battle of Arica / Flag Day Thu 7 Jun 2012
Saints Peter and Paul Fri 29 Jun 2012
Air Force Day Mon 23 Jul 2012
Independence Day Sat 28 Jul 2012
Independence Day (2nd) Sun 29 Jul 2012
Battle of Junín Mon 6 Aug 2012
Saint Rose of Lima Thu 30 Aug 2012
Battle of Angamos Mon 8 Oct 2012
All Saints' Day Thu 1 Nov 2012
Immaculate Conception Sat 8 Dec 2012
Battle of Ayacucho Sun 9 Dec 2012
Christmas Tue 25 Dec 2012
New Year's Day Tue 1 Jan 2013
Maundy Thursday Thu 28 Mar 2013
Good Friday Fri 29 Mar 2013
Labor Day Wed 1 May 2013
Battle of Arica / Flag Day Fri 7 Jun 2013
Saints Peter and Paul Sat 29 Jun 2013
Air Force Day Tue 23 Jul 2013
Independence Day Sun 28 Jul 2013
Independence Day (2nd) Mon 29 Jul 2013
Battle of Junín Tue 6 Aug 2013
Saint Rose of Lima Fri 30 Aug 2013
Battle of Angamos Tue 8 Oct 2013
All Saints' Day Fri 1 Nov 2013
Immaculate Conception Sun 8 Dec 2013
Battle of Ayacucho Mon 9 Dec 2013
Christmas Wed 25 Dec 2013
New Year's Day Wed 1 Jan 2014
Maundy Thursday Thu 17 Apr 2014
Good Friday Fri 18 Apr 2014
Labor Day Thu 1 May 2014
Battle of Arica / Flag Day Sat 7 Jun 2014
Saints Peter and Paul Sun 29 Jun 2014
Air Force Day Wed 23 Jul 2014
Independence Day Mon 28 Jul 2014
Independence Day (2nd) Tue 29 Jul 2014
Battle of Junín Wed 6 Aug 2014
Saint Rose of Lima Sat 30 Aug 2014
Battle of Angamos Wed 8 Oct 2014
All Saints' Day Sat 1 Nov 2014
Immaculate Conception Mon 8 Dec 2014
Battle of Ayacucho Tue 9 Dec 2014
Christmas Thu 25 Dec 2014
New Year's Day Thu 1 Jan 2015
Maundy Thursday Thu 2 Apr 2015
Good Friday Fri 3 Apr 2015
Labor Day Fri 1 May 2015
Battle of Arica / Flag Day Sun 7 Jun 2015
Saints Peter and Paul Mon 29 Jun 2015
Air Force Day Thu 23 Jul 2015
Independence Day Tue 28 Jul 2015
Independence Day (2nd) Wed 29 Jul 2015
Battle of Junín Thu 6 Aug 2015
Saint Rose of Lima Sun 30 Aug 2015
Battle of Angamos Thu 8 Oct 2015
All Saints' Day Sun 1 Nov 2015
Immaculate Conception Tue 8 Dec 2015
Battle of Ayacucho Wed 9 Dec 2015
Christmas Fri 25 Dec 2015
New Year's Day Fri 1 Jan 2016
Maundy Thursday Thu 24 Mar 2016
Good Friday Fri 25 Mar 2016
Labor Day Sun 1 May 2016
Battle of Arica / Flag Day Tue 7 Jun 2016
Saints Peter and Paul Wed 29 Jun 2016
Air Force Day Sat 23 Jul 2016
Independence Day Thu 28 Jul 2016
Independence Day (2nd) Fri 29 Jul 2016
Battle of Junín Sat 6 Aug 2016
Saint Rose of Lima Tue 30 Aug 2016
Battle of Angamos Sat 8 Oct 2016
All Saints' Day Tue 1 Nov 2016
Immaculate Conception Thu 8 Dec 2016
Battle of Ayacucho Fri 9 Dec 2016
Christmas Sun 25 Dec 2016
New Year's Day Sun 1 Jan 2017
Maundy Thursday Thu 13 Apr 2017
Good Friday Fri 14 Apr 2017
Labor Day Mon 1 May 2017
Battle of Arica / Flag Day Wed 7 Jun 2017
Saints Peter and Paul Thu 29 Jun 2017
Air Force Day Sun 23 Jul 2017
Independence Day Fri 28 Jul 2017
Independence Day (2nd) Sat 29 Jul 2017
Battle of Junín Sun 6 Aug 2017
Saint Rose of Lima Wed 30 Aug 2017
Battle of Angamos Sun 8 Oct 2017
All Saints' Day Wed 1 Nov 2017
Immaculate Conception Fri 8 Dec 2017
Battle of Ayacucho Sat 9 Dec 2017
Christmas Mon 25 Dec 2017
New Year's Day Mon 1 Jan 2018
Maundy Thursday Thu 29 Mar 2018
Good Friday Fri 30 Mar 2018
Labor Day Tue 1 May 2018
Battle of Arica / Flag Day Thu 7 Jun 2018
Saints Peter and Paul Fri 29 Jun 2018
Air Force Day Mon 23 Jul 2018
Independence Day Sat 28 Jul 2018
Independence Day (2nd) Sun 29 Jul 2018
Battle of Junín Mon 6 Aug 2018
Saint Rose of Lima Thu 30 Aug 2018
Battle of Angamos Mon 8 Oct 2018
All Saints' Day Thu 1 Nov 2018
Immaculate Conception Sat 8 Dec 2018
Battle of Ayacucho Sun 9 Dec 2018
Christmas Tue 25 Dec 2018
New Year's Day Tue 1 Jan 2019
Maundy Thursday Thu 18 Apr 2019
Good Friday Fri 19 Apr 2019
Labor Day Wed 1 May 2019
Battle of Arica / Flag Day Fri 7 Jun 2019
Saints Peter and Paul Sat 29 Jun 2019
Air Force Day Tue 23 Jul 2019
Independence Day Sun 28 Jul 2019
Independence Day (2nd) Mon 29 Jul 2019
Battle of Junín Tue 6 Aug 2019
Saint Rose of Lima Fri 30 Aug 2019
Battle of Angamos Tue 8 Oct 2019
All Saints' Day Fri 1 Nov 2019
Immaculate Conception Sun 8 Dec 2019
Battle of Ayacucho Mon 9 Dec 2019
Christmas Wed 25 Dec 2019
New Year's Day Wed 1 Jan 2020
Maundy Thursday Thu 9 Apr 2020
Good Friday Fri 10 Apr 2020
Labor Day Fri 1 May 2020
Battle of Arica / Flag Day Sun 7 Jun 2020
Saints Peter and Paul Mon 29 Jun 2020
Air Force Day Thu 23 Jul 2020
Independence Day Tue 28 Jul 2020
Independence Day (2nd) Wed 29 Jul 2020
Battle of Junín Thu 6 Aug 2020
Saint Rose of Lima Sun 30 Aug 2020
Battle of Angamos Thu 8 Oct 2020
All Saints' Day Sun 1 Nov 2020
Immaculate Conception Tue 8 Dec 2020
Battle of Ayacucho Wed 9 Dec 2020
Christmas Fri 25 Dec 2020
New Year's Day Fri 1 Jan 2021
Maundy Thursday Thu 1 Apr 2021
Good Friday Fri 2 Apr 2021
Labor Day Sat 1 May 2021
Battle of Arica / Flag Day Mon 7 Jun 2021
Saints Peter and Paul Tue 29 Jun 2021
Air Force Day Fri 23 Jul 2021
Independence Day Wed 28 Jul 2021
Independence Day (2nd) Thu 29 Jul 2021
Battle of Junín Fri 6 Aug 2021
Saint Rose of Lima Mon 30 Aug 2021
Battle of Angamos Fri 8 Oct 2021
All Saints' Day Mon 1 Nov 2021
Immaculate Conception Wed 8 Dec 2021
Battle of Ayacucho Thu 9 Dec 2021
Christmas Sat 25 Dec 2021
New Year's Day Sat 1 Jan 2022
Maundy Thursday Thu 14 Apr 2022
Good Friday Fri 15 Apr 2022
Labor Day Sun 1 May 2022
Battle of Arica / Flag Day Tue 7 Jun 2022
Saints Peter and Paul Wed 29 Jun 2022
Air Force Day Sat 23 Jul 2022
Independence Day Thu 28 Jul 2022
Independence Day (2nd) Fri 29 Jul 2022
Battle of Junín Sat 6 Aug 2022
Saint Rose of Lima Tue 30 Aug 2022
Battle of Angamos Sat 8 Oct 2022
All Saints' Day Tue 1 Nov 2022
Immaculate Conception Thu 8 Dec 2022
Battle of Ayacucho Fri 9 Dec 2022
Christmas Sun 25 Dec 2022
New Year's Day Sun 1 Jan 2023
Maundy Thursday Thu 6 Apr 2023
Good Friday Fri 7 Apr 2023
Labor Day Mon 1 May 2023
Battle of Arica / Flag Day Wed 7 Jun 2023
Saints Peter and Paul Thu 29 Jun 2023
Air Force Day Sun 23 Jul 2023
Independence Day Fri 28 Jul 2023
Independence Day (2nd) Sat 29 Jul 2023
Battle of Junín Sun 6 Aug 2023
Saint Rose of Lima Wed 30 Aug 2023
Battle of Angamos Sun 8 Oct 2023
All Saints' Day Wed 1 Nov 2023
Immaculate Conception Fri 8 Dec 2023
Battle of Ayacucho Sat 9 Dec 2023
Christmas Mon 25 Dec 2023
New Year's Day Mon 1 Jan 2024
Maundy Thursday Thu 28 Mar 2024
Good Friday Fri 29 Mar 2024
Labor Day Wed 1 May 2024
Battle of Arica / Flag Day Fri 7 Jun 2024
Saints Peter and Paul Sat 29 Jun 2024
Air Force Day Tue 23 Jul 2024
Independence Day Sun 28 Jul 2024
Independence Day (2nd) Mon 29 Jul 2024
Battle of Junín Tue 6 Aug 2024
Saint Rose of Lima Fri 30 Aug 2024
Battle of Angamos Tue 8 Oct 2024
All Saints' Day Fri 1 Nov 2024
Immaculate Conception Sun 8 Dec 2024
Battle of Ayacucho Mon 9 Dec 2024
Christmas Wed 25 Dec 2024
New Year's Day Wed 1 Jan 2025
Maundy Thursday Thu 17 Apr 2025
Good Friday Fri 18 Apr 2025
Labor Day Thu 1 May 2025
Battle of Arica / Flag Day Sat 7 Jun 2025
Saints Peter and Paul Sun 29 Jun 2025
Air Force Day Wed 23 Jul 2025
Independence Day Mon 28 Jul 2025
Independence Day (2nd) Tue 29 Jul 2025
Battle of Junín Wed 6 Aug 2025
Saint Rose of Lima Sat 30 Aug 2025
Battle of Angamos Wed 8 Oct 2025
All Saints' Day Sat 1 Nov 2025
Immaculate Conception Mon 8 Dec 2025
Battle of Ayacucho Tue 9 Dec 2025
Christmas Thu 25 Dec 2025
New Year's Day Thu 1 Jan 2026
Maundy Thursday Thu 2 Apr 2026
Good Friday Fri 3 Apr 2026
Labor Day Fri 1 May 2026
Battle of Arica / Flag Day Sun 7 Jun 2026
Saints Peter and Paul Mon 29 Jun 2026
Air Force Day Thu 23 Jul 2026

Preguntas frecuentes

What counts as a business day?

In CivicCalendar a business day is a Monday–Friday that is not a legal holiday in Perú. Saturdays and Sundays are not counted.

Is the start day included?

Yes. In “Between two dates” mode both dates are inclusive. In “Add business days”, counting starts on the start date if that date is a business day.

Are regional holidays considered?

National holidays and regional holidays defined for the country are used. If a regional holiday does not apply to your area, the result may differ.

Is this an official calculation?

It is indicative according to current legislation and calendars loaded on the site. For critical legal or labor deadlines, confirm with the relevant rule or authority.