PartialDate Type

[myokeeh]

I ask the following because as simple as date math may seem, I've learned enough that it is not.

I just found out about DateOnly and TimeOnly. Does it make sense to have a PartialDate type? There are situations where we have date data with the following cases:

• Only year is known.
• Year and month is known, but not day.
• Month and day is know, but not year.
• Less likely, but I suppose possible: Year and day known, but not month.

In some sense, it's kind of like DateYearOnly (I suppose that can be an int?), DateYearMonthOnly, DateYearDayOnly (less likely)

With the backing of proper/existing "date" implementations, such a type should weed out February 31 as invalid (or is it? 😉)

[Clockwork-Muse]

The catch is that such types are usually needed for writing calendaring applications.

If that's what you're writing, the types present in the BCL are going to be insufficient in general, and you are advised to use NodaTime.

[huoyaoyuan]

If the information consists of too few parts, there's little benifit than using integers.
Considering leap years, dates are only manipulatable when year is included.

[danmoseley]

@tarekgh

[tarekgh]

@myokeeh I don't think having partial date type make sense. In your scenarios, you can create DateOnly object with the default values of the missing date part. For example, if you have year and month without a day, you create DateOnly(year, month, 1). you can apply this for any case that is missing the date part. Doing that will allow you to perform the needed calculations.

If you can send more details about the exact scenario, you are using this partial dates and what calculations you are doing on that partial date, that can help understand what you need. doing Date calculation on dates missing parts will not make sense.

To give some example why partial date doesn't make sense, imagine you are missing the year and have the month and the day. you have the month as February and the day is 29. do you consider this a correct or wrong date?