{"id":756,"date":"2020-05-29T19:40:26","date_gmt":"2020-05-30T02:40:26","guid":{"rendered":"https:\/\/www.ghosh.com\/blog\/?p=756"},"modified":"2020-10-21T01:29:55","modified_gmt":"2020-10-21T08:29:55","slug":"converting-pre-1900-dates-in-excel","status":"publish","type":"post","link":"https:\/\/www.ghosh.com\/blog\/converting-pre-1900-dates-in-excel\/","title":{"rendered":"Converting Pre-1900 Dates in Excel"},"content":{"rendered":"

[playht_player width=”100%” height=”175″ voice=”Noah”]<\/p>\n<\/div>

I<\/span>t’s disappointing that Microsoft Excel still does not support dates before January 1, 1900.\u00a0 I recently was exporting data from another application into Excel and was painfully reminded of this limitation.\u00a0 Here’s a summary of how I converted and stored the mixed dates, some from before 1900 and some after.<\/p>\n

First, I decided to break down all dates and store the year, month, and day separately for each date — i.e., in separate columns.<\/p>\n

For the post-1900 dates, this was simple:<\/p>\n

\n

Year = YEAR(A1). Month = MONTH(A1).\u00a0 Day = DAY(A1).<\/p>\n<\/blockquote>\n

The dates prior to 1900 came in as large numbers like 4294966821.\u00a0 With some reference checks to original data, I realized that 4294967297 was equivalent to December 31, 1899 and that the difference was number of days.\u00a0 I used 4294966933 as my reference for January 1, 1899 and relative difference in number of days.<\/p>\n

\n

B1=A1-4294966933<\/p>\n<\/blockquote>\n

But I wanted to use Excel’s built in ability to account for leap years, etc, so I’d have to use a valid date.\u00a0 Thus, I added 1000 years to make the date valid:<\/p>\n

\n

C1=DATE(2899,1,1) + B1<\/p>\n<\/blockquote>\n

Then, remember to take a 1000 off of the year again:<\/p>\n

\n

Year = YEAR(C1)-1000. Month = MONTH(C1).\u00a0 Day = DAY(C1).<\/p>\n<\/blockquote>\n

Done!<\/p>\n

Below is example screenshot of formulas and values.\u00a0 I hope this saves someone a bunch of time.<\/p>\n<\/div>

Formulas<\/h2><\/div>
<\/span><\/div>

Values<\/h2><\/div>
<\/span><\/div>
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