datetime

[River Huang]

Dear All, Suppose I have the following data

* Example generated by -dataex-. To install: ssc install dataex
clear
input float timeid str10 time double time1
 1 "2010.06.17" -1.8934272e+12
 2 "2010.06.18" -1.8934272e+12
 3 "2010.06.20" -1.8934272e+12
 4 "2010.06.21" -1.8934272e+12
 5 "2010.06.22" -1.8934272e+12
 6 "2010.06.23" -1.8934272e+12
 7 "2010.06.24" -1.8934272e+12
 8 "2010.06.25" -1.8934272e+12
 9 "2010.06.27" -1.8934272e+12
10 "2010.06.28" -1.8934272e+12
end
format %tchh:MM time1

How can I combine `time' and `time1' into a standard Stata datetime/c format (say, "2010.06.17 08:00:00")?

[Nick Cox]

Why is time1 negative? In the example you've given it is constant and negative: is this always true? I find

. di %tc -1.8934272e+12
31dec1899 08:00:00

How are we supposed to think about that?

[William Lisowski]

Like Nick, I am curious how your times came to be expressed as relative to the last day of 1899. But given that they are,

generate double dt = dhms(date(time,"YMD"),hh(time1),mm(time1),ss(time1))
format dt %tc

will generate a Stata Internal Format datetime value, and assign the default format to it. For a format more to your liking, help datetime display formats will give you plenty of guidance.

[River Huang]

Hi, Nick: The question was taken from the Chinese Stata forum. I simply re-post the question and seek for answer. At this point, I am unable to reply why `time1' is negative (but is is the raw data from someone).

[River Huang]

Hi, William: As I replied to Nick, the question/data is from someone else. But your suggestion seems to be the answer to the question. Thanks a lot.