531 days are past since May 28, 2023
| Date | Weekday | Event | Country | Type |
|---|---|---|---|---|
| 28 May | Sunday | Republic Day | Armenia , Azerbaijan | Public |
| 28 May | Sunday | Pentecost | Åland Islands , Belgium , Caribbean Netherlands , Bouvet Island , Republic of the Congo , Switzerland , Curaçao , Denmark , Estonia , Faroe Islands , France , Gabon , Hungary , Iceland , Italy , Saint Kitts and Nevis , Saint Lucia , Liechtenstein , Monaco , Saint Martin , North Macedonia , Montserrat , New Caledonia , Netherlands , Norway , French Polynesia , Poland , Saint Pierre and Miquelon , Romania , Solomon Islands , Sweden , Saint Helena, Ascension and Tristan da Cunha , Slovenia , Svalbard and Jan Mayen , Senegal , Sint Maarten , French Southern Territories , United States , Saint Vincent and the Grenadines , British Virgin Islands , Wallis and Futuna , South Africa | Public |
| 28 May | Sunday | Mother's Day | Burkina Faso , Ivory Coast , Cameroon , Dominican Republic , Algeria , Western Sahara , Haiti , Morocco , Madagascar , Mali , Mauritius , Niger , Sweden , Senegal , French Southern Territories , Tunisia | Non Public |
| 28 May | Sunday | Passing of Zhabdrung Ngawang Namgyal | Bhutan | Public |
| 28 May | Sunday | Derg Downfall Day | Ethiopia | Public |
| 28 May | Sunday | Border Guards' Day | Tajikistan | Public |
| 28 May | Sunday | Carpet Day | Turkmenistan | Public |
| 28 May | Sunday | Kiev Day | Ukraine | Non Public |
| 28 May | Sunday | Indianapolis 500 | United States | Other |