Public holidays
1866, Brasil, Piauí
| # | Date | Public holiday |
|---|---|---|
| 1 | Monday, 1 January 1866 | Confraternização Universal |
| 2 | Tuesday, 13 February 1866 | Terça-feira de Carnaval |
| 3 | Friday, 30 March 1866 | Sexta Feira Santa ou Paixão de Cristo |
| 4 | Saturday, 21 April 1866 | Tiradentes |
| 5 | Tuesday, 1 May 1866 | Dia do Trabalho |
| 6 | Thursday, 31 May 1866 | Corpus Christi |
| 7 | Friday, 7 September 1866 | Independência do Brasil |
| 8 | Friday, 12 October 1866 | Nossa Senhora Aparecida |
| 9 | Friday, 19 October 1866 | Dia do Piauí |
| 10 | Friday, 2 November 1866 | Finados |
| 11 | Thursday, 15 November 1866 | Proclamação da República Brasileira |
| 12 | Tuesday, 25 December 1866 | Natal |