I want to enter a date in the page property, but just year. Obsidian doesn’t let me do this, and forces me to enter month and day. If I enter just year, it auto-fulls the rest of the date with January 1st. For example, if I enter “1563” as a value, it will be auto-filled as January 1st, 1563.
This may not be exactly what you’re looking for, but why don’t you just put a number property if it’s just the year? For the year, the date format doesn’t do anything in particular.
To be interpreted as a date it needs to include at least the month, but even then it is stored as the first of that month. So either you just need to get used to seeing it with the month/day appended, or you could store it as a pure number.
If the value for a given property is stored as a date somewhere, and just the number somewhere, you’ll might run into a little issue when writing dataview queries against that property. The number variants will then most likely be skipped.