how to print date format of POSIXct in r

Question

start <- as.POSIXct("2016-01-17")  
end <- start + as.difftime(72, units="days")  
for(i in seq(from=start, by=60*60*24*7, to=end)) {  
       print(i)  
}

As the codes show above, I try to print out the date after Year 2016 within 72 days. However, the output is always numbers such as 1453006800. I've tried everything I can think of including as.Date, as.Date(i, origin="2016-01-17 00:00:00 EST")....Thanks!

Try putting `class(i) <- class(start)` before `print(i)`, explained [here](http://stackoverflow.com/questions/6434663/looping-over-a-date-object-result-in-a-numeric-iterator) — Rich Scriven, Mar 31 '16 at 19:15

andrechalom · Accepted Answer · 2016-03-31T19:27:14.073

0

The problem here is that while "start" and "end" are POSIX date objects, "i" is not. This is evident by checking their structures:

> str(start)
 POSIXct[1:1], format: "2016-01-17"
> str(i)
 num 1.46e+09

You can use other looping function instead of "for", which seem to be coercing "i" to numeric. You can use a while loop like:

> i = start
> while (i < end) {
 i = i + 60*60*24*7
 print(i)
}

edited Mar 31 '16 at 19:27

answered Mar 31 '16 at 19:09

andrechalom

737
3
13

Thanks so much for the quick response! solution from Hadd E. Nuff : class(i) <- class(start) works quite well! – user5843090 Mar 31 '16 at 19:20

how to print date format of POSIXct in r

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