Question

Dates in DB2 AS/400 are an integer, containing the number of days since sometime around the turn of the 20th century.

Question 1: Does anyone know the IBM DB2/AS400 “zero” date? e.g.:

• 12/30/1899
• 12/31/1899
• 1/1/1900

Question 2: Given an “AS/400” date (e.g. 40010) how can you convert that to a CLR DateTime?

DateTime d = new DateTime(40010); //invalid

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Some other “zero” dates are:

• OLE Automation: 12/30/1899
• SQL Server: 1/1/1900

Answer 1

Question 1:

I have no idea what the start date is for DB2. Google isn’t very helpful anyway. Don’t you have any sample data you could use to figure it out?

Update: are you sure the date is stored as a number of days? I found this page that suggests otherwise.

Question 2:

Assuming 1900-01-01 as the start date in this example, where days is the AS/400 date value.

DateTime myDate = new DateTime(1900, 1, 1).AddDays(days);