| 1/1/1866, Mon | New Year's Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 1/2/1866, Tue | New Year's Holiday |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 1/3/1866, Wed | New Year's Holiday |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 1/4/1866, Thu | New Year's Holiday |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 1/5/1866, Fri | New Year's Holiday |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 1/6/1866, Sat | New Year's Holiday |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 1/7/1866, Sun | New Year's Holiday |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 1/7/1866, Sun | Orthodox Christmas Day |
- Religion
- Christian
- Disrespectful to Hold an Event
- –
|
| 1/14/1866, Sun | Orthodox New Years Day |
- Religion
- Christian
- Disrespectful to Hold an Event
- –
|
| 1/22/1866, Mon | Unification Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 3/8/1866, Thu | Women's Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 3/9/1866, Fri | Women's Day: Additional Observance Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 4/8/1866, Sun | Easter Sunday (Orthodox) |
- Religion
- Christian
- Disrespectful to Hold an Event
- –
|
| 4/9/1866, Mon | Easter Monday (Orthodox) |
- Religion
- Christian
- Disrespectful to Hold an Event
- –
|
| 4/30/1866, Mon | International Labor Day: Additional Observance Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 5/1/1866, Tue | International Labor Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 5/9/1866, Wed | Victory Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 5/27/1866, Sun | Orthodox Pentecost |
- Religion
- Christian
- Disrespectful to Hold an Event
- –
|
| 5/28/1866, Mon | Orthodox Pentecost Monday |
- Religion
- Christian
- Disrespectful to Hold an Event
- –
|
| 6/28/1866, Thu | Constitution Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 6/29/1866, Fri | Constitution Day: Additional Observance Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 7/28/1866, Sat | Orthodox Baptism of Kyiv Rus |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 8/24/1866, Fri | Independence Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 8/30/1866, Thu | Independence Day: Additional Observance Day |
- Religion
- –
- Disrespectful to Hold an Event
- –
|
| 12/31/1866, Mon | New Year's Eve |
- Religion
- –
- Disrespectful to Hold an Event
- –
|