Mysql cannot handle year values < 1. That means filtering for a date value like 0000-01-01 won't work with mysql. Additionally, dates like 0001-01-01 could under some circumstances not work either when the date in combination with the time zone would resolve to something like 0000-12-31 - for example when the server is located (and configured) in UTC, but the user running the query is in New York. This could be observed by setting the time zone manually using the filter_timezone query parameter.
Resolves https://vikunja.sentry.io/share/issue/42bce92c15354c109eb1e6488b6a542b/
Resolves https://vikunja.sentry.io/share/issue/ef81451b0c7b43f1bff2d3a86ba393bb/
754d56ca82