Excel parsing (xls) date error - excel

I'm working on a project where I have to parse excel files for a client to extract data. An odd thing is popping up here: when I parse a date in the format of 5/9 (may 9th) in the excel sheet, I get 39577 in my program. I'm not sure if the year is encoded here (it is 2008 for these sheets).
Are these dates the number of days since some sort of epoch?
Does anyone know how to convert these numbers to something meaningful? I'm not looking for a solution that would convert these properly at time of parsing from the excel file (we already have thousands of extracted files that required a human to select relevant information - re-doing the extraction is not an option).

Excel stores dates as the number of days since 0-JAN-1900 (so 1-JAN-1900 would have a value of "1"). You can find a really good breakdown of how Excel handles dates and times here:
Dates And Times In Excel
When dates appear on screen in Excel as "5/9", "May 9th", or some such, it is a trick of the formatting and is not representative of the underlying data value. It sounds like your parsing program is pulling the underlying value, not the formatted date. In order to suggest a fix, though, I need to know what your parsing program is (Excel macro, formula, outside code, etc.).

DateTime.FromOADate (if you're using .NET) is the method you want. Excel dates are stored as doubles. If you have dates in the first two months of 1900 you might get bit by the Excel 1900 leap year bug.
From http://msdn.microsoft.com/en-us/library/system.datetime.fromoadate.aspx:
Double-precision floating-point number
that represents a date as the number
of days before or after the base date,
midnight, 30 December 1899. The sign
and integral part of d encode the date
as a positive or negative day
displacement from 30 December 1899,
and the absolute value of the
fractional part of d encodes the time
of day as a fraction of a day
displacement from midnight. d must be
a value between negative 657435.0
through positive 2958466.0.

All you need to do is format the cells correctly. Or am I misunderstanding your question -- are you saying you want to do it OUTSIDE of Excel? I wasn't sure. I'll delete this answer if it turns out to be stupid.

Related

Convert Modified Julian Date to UTC Date in Excel

I am looking for a formula where I can put a 5 digit Modified Julian Date and have it convert it to today's date for me.
I did it in a way where I have a separate sheet with a table but although it works, I am looking for a way without the need of a separate table. Here is some information:
00000 should translate to 11-17-1858
58890 should translate to 02-11-2020
Every time the number goes up 1, it should go up 1 day. This needs to have leap years in consideration as well. Any help will be appreciated.
Here is a website that currently does the conversions:
http://www.csgnetwork.com/julianmodifdateconv.html
This has to be done without macros, literally need it in formula format.
Just subtract 15018 and format the result as a date.
Why 15018 and not 15020?
In Excel, 1-Jan-1900 value is 1
In your date scheme 15020 = 1-Jan-1900
But, if you had the number 15020 to convert and subtracted 15020 it would --> 0, not the desired 1.
Therefore we reduce the 15020 by 1 to 15019.
Next, there is a deliberate "bug" in Excel, widely discussed both on SO and the internet, whereby the year 1900 is erroneously classified as a leap year.
So for any date equivalent that is after 28-Feb-1900, we have to subtract an extra 1.
If you might be dealing with dates between 1/1/1900 and 2/28/1900 you will need to modify the formula to take that into account.

Change the Excel date input format?

I've been struggling with Excel (2016) date formats. I know how to change display formats for dates and cells but the problem I have is the input format for dates. If I input a date as "DD.MM" or "DD.MM.YYYY" it does recognize it as a date but if I input the date as "DD.MM." (with the second dot after the month), Excel does not recognize it as a date anymore. The column in question is formatted as short date.
Is there anything that can be done or is this by-design? If so, it seems really strange as at least in my country it's the official way to write the date containing that second dot after the month number when there is no year included in the date.
I've been searching and Googling for solution but couldn't find anything on this really. I appreciate all comments and help regarding this question!
SUMMARY/TL;DR:
Excel version is 2016, country is Finland and language is finnish
Excel accepts/recognizes these as dates: 12.5 or 30.8
Excel does NOT accept/recognize these as dates: 12.5. or 30.8.
The column in question is formatted as short date
The dot after the month seems to be screwing things up
Why is this happening? Can anything be done?
Kind regards,
Tenttu
Yes, it is/was by design. (Funny enough, my Excel won't allow dots, only dashes (-), so I couldn't even test if "15.8" works)
So, there's a slight chance that the language of Excel (the defaults of time (24 hours or AM/PM), dates (MM/DD or DD/MM), decimals (comma or dot) etc.) wouldn't allow the dot at after the month. Here's an example of a user that has that dot, and wants to get rid of it. So, your system language is a good candidate for why this wouldn't work for you.
However, I realize that the example linked above don't feature a date with a dot at the end. Which could suggest it is rather by design. For example, if I add a dot to a valid date or time, it will result in some #VALUE!-error. And that's because of how Excel is programmed to convert text to a date - and remember, dates are actually just really large numbers. So, adding a dot at the end makes that conversion "impossible". We might think it's as easy as to remove a dot, but in programming, we need to program that explicitly to do that, and I'm leaning towards there is no such operation done during text to date conversion (certainly not on my system, as I get #VALUE!).
One work-around is to strip the ending dot from the date to make it a valid date. So, you can import sheets with dates with dots at the end, then strip them away, and you'll be good to go!

Formatting Existing Excel Cells to Time Format Without Date

I'm working on an excel 2010 sheet where I mark down the date and time an event happens. The date is in one column, and auto formats to 17-Nov when I would type in 11-17 (I was fine with this). The time is in a separate column.
I am trying to find the average time an event occurred, without regard to the date, so I would use =AVERAGE(C1:C10). However, I only receive a date back (like 17-APR).
I did not format the cells before I began to enter in data, and I would simply type in a 3:27pm event as 1527, and no reformatting would happen.
Now, when I attempt to reformat the column to hhmm, all the numbers entered so far turn to 0000. When I try to edit the 0000, it is formatted as 6/13/1906 12:00:00 AM.
What I want to do is have the time formatted as hhmm and not include a date in the cell, and be able to run formulas on it, such as the average time an even occurred.
Summary:
*Currently time is entered simply as ####. I entered 3:27pm as 1527.
*Trying to reformat the time column results in 0000 in all cells in the column that previously had a ####.
*Modifying the 0000 displays as 6/13/1906 12:00:00 AM
*I want to format the time as hhmm so I can simply type in 2357, and have it display as 2357, but understand I mean 11:57pm, and let me take averages.
*Hell, even being able to enter 1547 and have it auto format to 15:47 or 3:47p would be great.
Thanks for reading my question!
An easy way to apply an autoformat (though Excel won't see it as a true "Time") is to go into Format Cells>Custom> and use ##":"##. This will turn 1245 into 12:45. Mind you, this will be a text string so if you copy it to another cell and then apply a time, it will show as 12:00:00. Excel will also not be able to run formulas on it, but it's a quick and dirty way to make it look pretty.
Another option is to have a formula such as =TIME(LEFT(A1,2),RIGHT(A1,2),) where A1 would be replaced with the cell you are actually referencing. This will convert the number to a time that Excel will recognize as a time allowing you to run other functions on it, but requires another column.
If you are entering the times as 4-digit numbers, you'll need to do a calculation to get the hours and minutes, then use the TIME function to get an actual time:-
=TIME(A1/100,MOD(A1,100),0)
Another way is
=LEFT(A1,2)/24+RIGHT(A1,2)/1440
but then you have to format the result as a time.
Excel sees a number like 1547 as approximately 4 years on from 1st January 1900 if you format it as a date, so it will come out as something like 26/3/1904 in UK format or 3/26/1904 in US-style format.
Note that the time function can only give you values up to 23:59:59 (stored as 0.999988426), but the second method will give you a datetime value with one or more days as the whole number part. This can be useful if you want to do calculations on times spanning more than one day.
The above behaviour is because dates and times are stored as real numbers with the whole number part representing days and the decimal part representing fractions of a day (i.e. times). In spite of misleading information from Microsoft here, dates actually start from 31/12/1899 (written as 0/1/1900) with serial number 0 and increment by 1 per day from then on.

number to date conversion in excel (weird format)

I have collected some details from sql and it shows a birthdates as following (each line represents a different birthdate):
-294022800
649119600
-138675600
49158000
32396400
631152000
-2147483648
731894400
-408067200
522025200
I was trying to change them in excel using this formula:
=DATE(INT(A1/10000),INT((A1-10000*INT(A1/10000))/100),A1-(100*INT(A1/100)))
But it didnt work well, it must be in different format. Do you know what sort of format it is and how to convert it to date in excel? why some of numbers are negatives?
Can this be the EPOCH format? how to change it to normal human date in excel?
My guess would be that they are unix timestamps http://en.wikipedia.org/wiki/Unix_time
In excel, you can use something like:
=(((A1/60)/60)/24)+DATE(1970,1,1)
Although, you will have to watch out for the fact that your datetimes seem to include daylight savings offsets. (Some of them are multiples of a day (24*60*60), but others are an hour out). I'm not sure why you have a non-hour multiple in there (-2147483648), possibly some quirk of the original system.
Source: http://spreadsheetpage.com/index.php/tip/converting_unix_timestamps/
Unix timestamps can be converted with this formula
=A1/86400+DATE(1970,1,1)
The Unix timestamp is seconds since 1/1/1970 so birthdates before then would be negative. [one of the birthdates translates to 1901 - is that right? You'll have problems if any of the dates are before 1900 because Excel doesn't recognise those dates]
ok, I figured it out. This is the formula:
=(A1-(4*3600))/86400+25569

Joining a date and time into a single cell in Excel / VBA

I have to report basically the same information from inspections to two different clients, both of whom have provided me with an Excel spreadsheet in their own preferred format, and password protected. I have put the two sheets into my own workbook, and have managed to get 'almost' all the data on both sheets to populate from my own data. Where I am stuck though is on the time logs.
Client 'A' has each time and date in a single column, in the format "12.29.12 14:30". Client 'B' has two columns, date as "12/29/12" in the first, and time as "1430" in the second.
I'm trying to avoid having to type all the same dates and times twice - it can be several dozen lines - both to save effort and to avoid errors. What I really need to do is either concatenate the date and time from client 'B's report and put it into client 'A's, or split the date and time up in 'A's so I can put it ito 'B's. I've tried several approaches, but just end up with error codes or meaningless numbers.
Can anyone point me in the right direction?
Thanks,
Richard
Never mind... the very next thing I tried worked :-)
To anyone else reading this, the trick is not to concatentate the date and time values, but to add them together.
Richard
As you later pointed out in your own question, in order to manipulate date/times in Excel, you should add instead of concatenating.
The reason for this is that Excel stores all date/times as a number representing the number of days since January 1, 1900*. This number is stored as a 8-byte double.
Use Excel number formats to display the date/time format that you desire.
If you find in a worksheet that some cell's dates are in fact stored as text, use the DATEVALUE function.
*By default, Excel 2010 for Windows uses the number of days since 1900. There is an option to use the number of days since 1904 for compatibility with other versions.

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