Hello everyone! I'm writing a lot of scripts these days at work but now I'm stuck...
Basically I need to analyze a parameter (a String) and see if the date it contains is later than another one...
I know it could be a "nooby" question, but the fact that the parameter is a string and the control is on a date totally confuses me...
Is it something as simple as: if parameter("DataAct") > 01/01/2010 ?!?!
Have a look at DateDiff function: http://www.w3schools.com/vbscript/func_datediff.asp. Example:
diff = DateDiff("d", "02/19/2015", "02/20/2015") ' difference in days
diff = DateDiff("h", "02/19/2015", "02/20/2015") ' difference in hours
diff = DateDiff("n", "02/19/2015", "02/20/2015") ' difference in mins
diff = DateDiff("s", "02/19/2015", "02/20/2015") ' difference in seconds
To calculate the difference, you would need to parse out the date from the string and use DateDiff.
The order of dates determines the output. In the example above, all values will be positive. If you revert them, output would result in negative. Providing the same date/time will result in 0.
diff = DateDiff("d", "02/20/2015", "02/19/2015") ' output = -1
diff = DateDiff("d", "02/20/2015", "02/20/2015") ' output = 0
Related
Microsoft Excel does not recognise pre-1900 dates and there is plenty of information online which documents this, including the question here.
The best work around (which many other posts link to) seems to be at ExcelUser
However, although the work around gets Excel to recognise a pre-1900 date as a date, it still does not allow it to be used in calculations e.g. when wanting to calculate the number of years since a pre-1900 date.
My question is whether the work around described at ExcelUser can be modified to allow the result to be used in a calculation.
To put things simply, for example, I want to calculate in Excel the number of years since 1/4/1756 - is this possible?
Or does another solution have to be adopted? Perhaps there are plug-ins which address this problem?
First of all I highly recommend to use the ISO 8601 format yyyy-mm-dd for dates because even if you only have strings and no real numeric dates this is properly sortable and the only date format that is defined clearly and cannot be misinterpret like 02/03/2021 where no one can ever say if it is mm/dd/yyyy or dd/mm/yyyy because both actually exist.
Since old dates cannot be real numeric dates but only entered as strings (looking like a date) that means misinterpretation needs to be avioded or you get wrong results. Therefore a date format that cannot be misinterpret is a clear advantage.
Second there is more than one way to calculate "how many years since the birth of Mr. X": For example lets take the birthday of Maryam Mirzakhani 1977-05-12 compared to the date today 2021-04-15. Today she would not have had birthday yet this year and therefore she would be 43 years old. But this year she would have turned 44 years (2021 - 1977 = 44). So the question needs to be asked more precisely. Either "how old would Mr. X be today?" or "how old would Mr. X be this year". The calculation for that would be different.
So let's start and assume the following data. We already know the fact that Excel cannot calculate with dates before 1900. You can see that if we enter pre-1900 dates that they are formatted as string (red dates) and post-1900 dates get formatted as numeric dates (green dates).
Image 1: #WERT! means #VALUE! (sorry for the German screenshot).
Also in column D where the formula =DATEDIF($B2,TODAY(),"y") was used the string dates cannot be calculated with. But since VBA can actually handle pre-1900 dates we can write our own UDF (user defined function) for that. Since as I explained above there is 2 different methods to calculate there is 2 different functions:
OldDateDiff(Date1, Date2, Interval) called like =OldDateDiff($B2,TODAY(),"yyyy")
OldDateAge(Date1, Date2) called like =OldDateAge($B2,TODAY())
Option Explicit
Public Function OldDateDiff(ByVal Date1 As Variant, ByVal Date2 As Variant, ByVal Interval As String) As Long
Dim RetVal As Long 'variable for the value we want to return
Dim localDate1 As Date
If VarType(Date1) = vbDate Or VarType(Date1) = vbDouble Then 'check if Date1 is numeric
localDate1 = CDate(Date1) 'if numeric take it
ElseIf VarType(Date1) = vbString Then 'check if Date1 is a string
localDate1 = ISO8601StringToDate(Date1) 'if it is a string convert it to numeric
Else 'neither string nor numeric throw an error
RetVal = CVErr(xlErrValue)
Exit Function
End If
Dim localDate2 As Date 'same as for Date1 but with Date2
If VarType(Date2) = vbDate Or VarType(Date2) = vbDouble Then
localDate2 = CDate(Date2)
ElseIf VarType(Date2) = vbString Then
localDate2 = ISO8601StringToDate(Date2)
Else
RetVal = CVErr(xlErrValue)
Exit Function
End If
If localDate1 <> 0 And localDate2 <> 0 Then 'make sure both dates were filled with values
RetVal = DateDiff(Interval, localDate1, localDate2) 'calculate the difference between dates with the desired interaval eg yyyy for years
End If
OldDateDiff = RetVal 'return the difference as result of the function
End Function
Public Function OldDateAge(ByVal Date1 As Variant, ByVal Date2 As Variant) As Long
Dim RetVal As Long 'variable for the value we want to return
Dim localDate1 As Date
If VarType(Date1) = vbDate Or VarType(Date1) = vbDouble Then 'check if Date1 is numeric
localDate1 = CDate(Date1) 'if numeric take it
ElseIf VarType(Date1) = vbString Then 'check if Date1 is a string
localDate1 = ISO8601StringToDate(Date1) 'if it is a string convert it to numeric
Else 'neither string nor numeric throw an error
RetVal = CVErr(xlErrValue)
Exit Function
End If
Dim localDate2 As Date 'same as for Date1 but with Date2
If VarType(Date2) = vbDate Or VarType(Date2) = vbDouble Then
localDate2 = CDate(Date2)
ElseIf VarType(Date2) = vbString Then
localDate2 = ISO8601StringToDate(Date2)
Else
RetVal = CVErr(xlErrValue)
Exit Function
End If
If localDate1 <> 0 And localDate2 <> 0 Then 'make sure both dates were filled with values
RetVal = WorksheetFunction.RoundDown((localDate2 - localDate1) / 365, 0)
'subtract date1 from date2 and divide by 365 to get years, then round down to full years to respect the birthday date.
End If
OldDateAge = RetVal 'return the age as result of the function
End Function
' convert yyyy-mm-dd string into numeric date
Private Function ISO8601StringToDate(ByVal ISO8601String As String) As Date
Dim ISO8601Split() As String
ISO8601Split = Split(ISO8601String, "-") 'split input yyyy-mm-dd by dashes into an array with 3 parts
ISO8601StringToDate = DateSerial(ISO8601Split(0), ISO8601Split(1), ISO8601Split(2)) 'DateSerial returns a real numeric date
' ≙yyyy ≙mm ≙dd
End Function
Note that here column B contains 2 different kind of data. Strings (that look like a date) and real numeric dates. If you sort them, all the numeric dates will sort before the string dates (which is probably not what you want). So if you want this to be sortable by birthday column make sure you turn all dates into strings. This can be done by adding an apostrophe ' infront of every date. This will not display but ensure the entered date is considered to be a string.
If your date is in an unambiguous format (eg ISO or a format corresponding to your Windows Regional Settings, or a real date if after 1900), you can use VBA which will recognize early dates.
Function Age(dt As Date)
Age = DateDiff("yyyy", dt, Date)
End Function
You should be aware that, because of how the function calculates years differences, depending on what you want exactly for a result, you may need to adjust the answer if the birthdate is before/after today's date.
In other words, if the day of the year of the birthdate is after the day of the year of Today, you may need to subtract 1 from the result.
But this should get you started.
There's a much easier way than the accepted answer. Simply convert your dates to Unix time:
Function nUnixTime(dTimestamp As Date) As LongLong
' Return given VB date converted to a Unix timestamp.
Const nSecondsPerDay As Long = 86400 ' 24 * 60 * 60
nUnixTime = Int(CDbl(CDate(dTimestamp) - CDate("1/1/1970"))) * nSecondsPerDay
End Function
Unix time is the number of seconds since Jan. 1, 1970, with times before that date being negative. So if you convert your dates to Unix time, you can just subtract them and divide the result by 86,400 to have the difference in days, or by 31,557,600 for years (31,557,600 = 60 * 60 * 24 * 365.25).
Example results of the above VB function called from Excel:
Column A
Column B formula
Column B value
2/2/2022
=nUnixTime(A1)
1,643,760,000
1/1/1970
=nUnixTime(A2)
0
12/14/1901
=nUnixTime(A3)
-2,147,472,000
12/13/1901
=nUnixTime(A4)
-2,147,558,400
1/1/1900
=nUnixTime(A5)
-2,208,988,800
1/1/1800
=nUnixTime(A6)
-5,364,662,400
1/1/100
=nUnixTime(A7)
-59,011,459,200
The reason I included the two dates in 1901 is because their magnitudes in Unix time are just smaller than and just larger than the largest magnitude of a signed 32-bit integer, i.e., a Long in VBA. If the output of the above function were a Long, then values for dates before Dec. 14, 1901 would be the error #Value!. That is the reason the output of the function is defined as LongLong, which is VBA's signed 64-bit integer.
I need to trace expire date of materials. To do so, I need to search for specific time interval (e.g. 80 days prior and 40 days later from today).
First, I set today's date in dd/mm/yyyy format. Then, take two input from user such that the first one is to identify the date after today (say x), and the second input for how many days before today (say y).
Now, I need to compare (today + x) and (today - y) dates with expiration date of materials such that whether shelf life of the materials fall within [y,x] interval. However, I am stuck.
I define rear and further as inputBox variables. Value entered to rear would be assigned to the variable x and give "rear" days prior today, and value entered to further would be assigned to variable y and take us "further" days after.
Here I identify today's date ("G1" cell) and time interval with x and y dates as well
Public Sub date()
Dim DateToProcess As Date
DateToProcess = Date
BUBD.Cells.Range("G1") = DateToProcess
rear = InputBox("How many days do you want to trace back?")
x = DateAdd("d", -rear, CDate(Range("G1")))
further = InputBox("How many days after do you want to check?")
y = DateAdd("d", further, CDate(Range("G1")))
End Sub
Then I want to compare materials BUBD with x and y
If rngRisk(j) > x Or rngRisk(j) < y
When I compare x and y with expire dates in rngRisk column, all values are pasted regardless of being in the interval
How can I compare expire dates of materials with x and y?
If I understood correctly your code is not being able to compare dates.
I will assume that rngRisk(j) is a Excel cell, in that case what might be happening is the type of the data in the cell is coming on the wrong format. If the cell is formated as Date, you could do rngRisk(j).Value2. It should returns the date or the number of days since 1900 until the specified date.
OBS: x and y should be date or long type in order to compare dates
in case the cell is in date format
If rngRisk(j).Value2 > x
in case the cell is in text format
If CDate(rngRisk(j).Value2) > x
Edit:
Sample for compare dates
Sub CompareDates()
Dim rngDates As Range
Dim initialDate As Date
Dim finalDate As Date
Dim dateInColumn As Variant
initialDate = Date ' today
finalDate = Date + 3 ' 3 days from now
Set rngDates = ActiveSheet.Range("b2:b21") ' range with dates
For Each dateInColumn In rngDates
If dateInColumn.Value2 > initialDate And dateInColumn.Value2 < finalDate Then
MsgBox CDate(dateInColumn.Value2) & " is in between " & initialDate & " and " & finalDate
End If
Next
End Sub
Welcome!
Firstly, always use Option Explicit on the very top of your code before your Subs.
This will force you to declare your variables which will save you from errors that have to do with data types.
Second, x, y and rngRisk should be declared as date in order to be reliably compared to a date.
Finally, you can just add integers to a variable declared as date like so
dim tomorrow as date
tomorrow = Date + 1
I have a series of dates and some corresponding values. The format of the data in Excel is "Custom" dd/mm/yyyy hh:mm.
When I try to convert this column into an array in Matlab, in order to use it as the x axis of a plot, I use:
a = datestr(xlsread('filename.xlsx',1,'A:A'), 'dd/mm/yyyy HH:MM');
But I get a Empty string: 0-by-16.
Therefore I am not able to convert it into a date array using the function datenum.
Where do I make a mistake? Edit: passing from hh:mm to HH:MM doesn't work neither. when I try only
a = xlsread('filename.xlsx',1,'A2')
I get: a = []
According to the documentation of datestr the syntax for minutes, months and hours is as follows:
HH -> Hour in two digits
MM -> Minute in two digits
mm -> Month in two digits
Therefore you have to change the syntax in the call for datestr. Because the serial date number format between Excel and Matlab differ, you have to add an offset of 693960 to the retrieved numbers from xlsread.
dateval = xlsread('test.xls',1,'A:A') + 693960;
datestring = datestr(dateval, 'dd/mm/yyyy HH:MM');
This will read the first column (A) of the first sheet (1) in the Excel-file. For better performance you can specify the range explicitly (for example 'A1:A20').
The code converts...
... to:
datestring =
22/06/2015 16:00
Edit: The following code should work for your provided Excel-file:
% read from file
tbl = readtable('data.xls','ReadVariableNames',false);
dateval = tbl.(1);
dateval = dateval + 693960;
datestring = datestr(dateval)
% plot with dateticks as x-axis
plot(dateval,tbl.(2))
datetick('x','mmm/yy')
%datetick('x','dd/mmm/yy') % this is maybe better than only the months
Minutes need to be called with a capital M to distinguish them from months.
Use a=datestr(xlsread('filename.xlsx',1,'A:A'),'dd/mm/yyyy HH:MM')
Edit: Corrected my original answer, where I had mixed up the cases needed.
I tried with this. It works but it is slow and I am not able to plot the dates at the end. Anyway:
table= readtable ('filename.xlsx');
dates = table(:,1);
dates = table2array (dates);
dates = datenum(dates);
dates = datestr (dates);
I have a VBA script at the moment that reads in 6 values as integers. 3 values for date, month, and year and 3 of the same type from a different location. I'd like to take the values and check if there has been more than a year to pass between them. DateDiff seems like the easiest way to handle this, however that function reads in the values as one DateValue (ie March 20, 2015) and my values are returned individually (08,08,2015).
I wrote a function that stores each value into a var and then using those individually I concat them into a format that DateValue can use.
This works, however I am curious if there is another(better) way to handle this problem?
Thanks in advance.
The function DateSerial(2015,3,4) will return the date for 3/4/2015, and with both of your dates in that format, you can subtract the one date from the other, and if the (absolute value of the) difference is > 365 then you know that they are over a year apart.
Dim A As Date
A = DateSerial(2015, 3, 4)
Dim B As Date
B = DateSerial(2014, 3, 2)
Dim C As Integer
C = Abs(A - B)
MsgBox C & " days between"
I am trying to find out the difference between the system date and the date stored in the worksheet. If the difference between them is > 30 days, the result is true, else the result is false
Dim result as boolean
Dim sDate as string
sDate = Date
if Worksheets("dates").Cells(1,1) - sDate > 30 then 'how do I do this?
result = true
else
result = false
end if
How do I find out the difference in days between the system date and the date stored in the worksheet? The date in the worksheet can be a past date, too.
I wonder why I rarely see people using the date functions.
You can also use this:
if DateDiff("d", date1, date2) > 30 then
in this case, date1 would be CDate(Worksheets("dates").Cells(1,1))
and date2 would be sdate (either cast with CDate or dim'd as a date as Jeff said.
"d" means we are getting the difference in days. Here are the intervals for years, months, etc. in VBA:
yyyy - Year
q - Quarter
m - Month
y - Day of year
d - Day
w - Weekday
ww - Week
h - Hour
n - Minute
s - Second
Try this:
if CDate(Worksheets("dates").Cells(1,1)) - sDate > 30 then
sDate is a STRING, which is NOT a Real Date!
Convert your string to a date, using either the CDate() function or the DateValue() function.
However, there is a caveat in this kind of conversion. These conversion will handle the following structures:
yyyy/mm/dd
yyyy/m/d
mm/dd/yyyy
m/d/yyyy
These will not be correctly converted
dd/mm/yyyy
d/m/yyyy
And avoid using any 2-digit year.
I would advise using the DateSerial() function for date conversion.
So regarding your code, assuming that the values on yor sheet are actually dates (to be certain, simply select the column and change the Number Format to GENERAL. If they are real dates, each will display a PURE NUMBER. Remember to hit UNDO to get your Date Format back)
Dim result As Boolean
If Worksheets("dates").Cells(1, 1).Value - Date > 30 Then
result = True
Else
result = False
End If