I have a date variable in Stata which is stored as a double which looks like this:
Date
07dec2012
08jan2018
.
.
.
The display format is: %td. I would like to convert this variable into a long format so that I can use it for a fixed effects analysis. Is there an easy way of doing so?
long is a variable or storage type, not a (display) format.
Daily dates that arise in most practice can be stored as int variables, so compress will achieve that.
. clear
. set obs 1
Number of observations (_N) was 0, now 1.
. gen double date = mdy(1, 8, 2018)
. compress
variable date was double now int
I wasn't aware that being double would be a problem for what you want to do, and I can't see why long should be preferred over int.
EDIT The reported range of dates can be tested too
. clear
. set obs 2
Number of observations (_N) was 0, now 2.
. gen double Date = cond(_n==1, -19903, 22280)
. format Date %td
. l
+-----------+
| Date |
|-----------|
1. | 05jul1905 |
2. | 31dec2020 |
+-----------+
. compress Date
variable Date was double now int
(12 bytes saved)
Related
I am trying to simply count the months between two dates in Stata, given in year-month (%tm) format, data storage type being int. Basically, I want to do what the datediff(d1, d1, "month") function does in Stata 17 - except I have Stata 15. I saw a few other forums about this, but they all talked about solutions for a year-month-day format, which doesn't seem to work for me. Is there a way to do this?
As both variables are numeric and the units are consistent, no special function is needed as a subtraction gives the answer.
. clear
. set obs 1
Number of observations (_N) was 0, now 1.
. gen now = ym(2022, 7)
. gen lastyear = ym(2021, 7)
. format now lastyear %tm
. di now - lastyear
12
. gen diff = now - lastyear
. l
+--------------------------+
| now lastyear diff |
|--------------------------|
1. | 2022m7 2021m7 12 |
+--------------------------+
Hello currently my dates are stored as numeric in the form of 40547. How can I convert these to MMDDYY10.?
data SevenSec11;
set Seven11;
DateRecieved = input(put(DateRecieved, 8.), MMDDYY10.);
format DateRecieved MMDDYY10.;
run;
How to convert it depends on what the value represents. If it is dates as stored by Excel then change the offset value. If it is supposed to represent MMDDYY values then use the Z6. format in your PUT() function call.
data test;
input num ;
sasdate1 = num + '30DEC1899'd ;
sasdate2 = input(put(num ,z6.),mmddyy10.);
format num comma7. sasdate: yymmdd10. ;
cards;
40547
;
Result:
Obs num sasdate1 sasdate2
1 40,547 2011-01-04 1947-04-05
Note that using Y-M-D order for dates will eliminate confusion that truncated leading zeros can cause. It will also prevent half of your audience from confusing April 5th with May 4th.
After a data export I get a string variable with "2017/02/22 1320:35 +000 4".
Through:
compute #TS = char.index(Timestamp_1, " ").
string date (A10).
compute date = char.substr(Timestamp_1,1,#TS).
alter type date (A10 = SDATE10).
I manage to get the date in a separate variable.
The same:
string time (A8).
compute time = char.substr(Timestamp_2,#TS+1,7).
alter type time (A8 = TIME8).
doesn't work for the time because it is in the 'hhmm:ss' format. How do I change the string variable '1320:35' into a time variable '13:20:35'?
You can insert a ":" manually into the time string by using the concat function before you alter the type.
COMPUTE time = CONCAT(CHAR.SUBSTR(time,1,2),":",(CHAR.SUBSTR(time,3))).
Another approach would be to extract hours, minutes and seconds from Timestamp variable individually and to use these elements inside the TIME.HMS function:
COMPUTE #hh = NUMBER(CHAR.SUBSTR(Timestamp_1,TS+1,2),F2).
COMPUTE #mm = NUMBER(CHAR.SUBSTR(Timestamp_1,TS+3,2),F2).
COMPUTE #ss = NUMBER(CHAR.SUBSTR(Timestamp_1,TS+6,2),F2).
COMPUTE time = TIME.HMS(#hh,#mm,#ss).
EXECUTE.
FORMATS time (TIME8).
Statistics has a datetime format and, new in V24, an ISO 8601 timestamp format, YMDHMS. If the string is converted to a regular date/time value, then the XDATE.DATE and XDATE.TIME functions can be used to extract the pieces. The Date and Time wizard may accommodate the format you have (not sure about that +000 4 part at the end).
I'm trying to compare a file's modified date with a specific date.
What I have is this:
If FormatDateTime(objFile.DateLastModified,vbShortDate) = specificDate Then
'Do something
End if
I've tried using IsDate and a variable with a value of #11/9/2015# but always returns false. I can't figure out how to set the variable "specificDate" to 11/9/2015.
If you are comparing the date only (but not the time), then you have to cut off the fractional part of the last modified value, since integer part represents days, and fractional part - hours, minutes and seconds. After any changes convert the values back to Date type with CDate(), as well as date containing string before the comparison.
Sub Test()
dtSpecificDate = CDate("11/9/2015")
With CreateObject("Scripting.FileSystemObject").GetFile("C:\Test\tmp.txt")
dtLastModified = CDate(Int(.DateLastModified))
End With
If dtLastModified = dtSpecificDate Then
' Do something
End If
End Sub
I am trying to maintain a table using some panel data. I have all the data outputting fine, but I am having difficulty getting the correct dates to display. The method I am using is the following:
gen ymdny = date(date,"MDY"); /*<- date var from panel dataset that i import*/
sort name ymdny;
summ ymdny;
local lastdate : disp %tdM-D r(max);
local lastdate2 : disp %tdM-D (r(max)-1);
local lastw : disp %tdM-D (r(max)-7);
This would work fine if the data were daily, but the dataset I have is actually business daily (ie. missing for the weekends and bank national holidays). It seems silly but I have not been able to figure out a workaround that does the job. Ideally - there is a function that i can use to print the corresponding date to a particular value.
For example:
gen resbal_1d = round(l1.resbal,0.1);
gen dateOf = dateOf(resbal_1d); /* <- pseudocode example of what I would like */
I'm not sure what you're asking for but my guess is that you want to see a human readable form date as the output, given a numerical input. (This is your last sentence.) So simply try something like:
display %td 10
The format is important as the following shows (see help format):
display %tq 10
Same numerical input, different format, different output.
Two other examples from the manual:
* string to integer
display date("5-12-1998", "MDY")
* string to date format
display %td date("5-12-1998", "MDY")
As for your example code, I don't get what you're aiming for. In effect, you can summarize the date variable because in Stata, dates are just integers. It's legal but couldn't say if it's good form. Below a simple example.
clear all
set more off
set obs 10
gen date = _n // create the data
format date %td // give date format
list
summarize date
local onedate = r(max)
display %td `onedate'
Some references:
[U] 24 Working with dates and time
help datetime
help datetime business calendars
http://www.stata.com/support/faqs/data-management/creating-date-variables/
http://www.ats.ucla.edu/stat/stata/modules/dates.htm
(Maybe you can explain with more detail and context what it is you want.)
Edit
Your comment
I do not see how this helps with the date output. For example,
displaying r(max) - 1 on a monday will still display the sunday date.
does not explain, at all, the problems you're having with Stata's business calendars.
I'm adding what is basically an example taken from the help file I already referenced. I do this with the hope of convincing you that (re)-reading the help files is worthwhile.
*clear all
set more off
* import string dates
infile str10 sdate float x using http://www.stata-press.com/data/r13/bcal_simple
list
*----- Regular dates -----
* create elapsed dates - Stata's way of managing dates
generate rdate = date(sdate, "MD20Y")
format rdate %td
drop sdate x
list
* compute previous and next dates
generate tomorrow1 = rdate + 1
format tomorrow1 %td
generate yesterday1 = rdate - 1
format yesterday1 %td
list
*----- Business dates -----
* convert regular date to business dates
generate bdate = bofd("simple", rdate)
format bdate %tbsimple
* compute previous and next dates
generate tomorrow2 = bdate + 1
format tomorrow2 %tbsimple
generate yesterday2 = bdate - 1
format yesterday2 %tbsimple
order yesterday1 rdate tomorrow1 yesterday2 bdate tomorrow2
list
/*
The stbcal-file for simple, the calendar shown below,
November 2011
Su Mo Tu We Th Fr Sa
---------------------------
1 2 3 4 X
X 7 8 9 10 11 X
X 14 15 16 17 18 X
X 21 22 23 X X X
X 28 29 30
---------------------------
*/
Notice that if you add or substract 1 from a regular date, then business days are not taken into account. If you do the same with a business calendar date, you get what you want. Business calendars are defined by .stbcal files; the example uses a built-in calendar called simple. You maybe need to make your own .stbcal file but it is not difficult. Again, the details are in the help files.