问题
I have a variable date with timestamps:
27.03.2016 01:30
27.03.2016 02:00
27.03.2016 02:30
The format is character.
After using
as.POSIXct(strptime(data.frame$date, format = "%d.%m.%Y %R"))
two of the 17568 observations are NA. The others are printed correctly. Why does it happen?
来源：https://stackoverflow.com/questions/42504670/nexpected-na-after-using-as-posixctstrptime