This is a followup to bug 158467 The Calc - Calculate - Date setting defines what should be considered the 0 value in date calculations. This setting is stored as a set of 3 keys[1], which is a bit overcomplicated for such a simple 3 state radio button. It would be a somewhat simpler implementation to replace these 3 keys with a single (for example:) ZeroDate key. Code pointers: [1] https://opengrok.libreoffice.org/xref/core/officecfg/registry/schema/org/openoffice/Office/Calc.xcs?r=464d5f12#45 - the keys in question https://opengrok.libreoffice.org/xref/core/sc/source/core/tool/docoptio.cxx?r=14001bc7#155 - the relevant ScDocCfg class