Creating a date/time object by two string objects

Question

I have two objects named "Date" and "Time". The date is in YYYY.mm.dd and time is in HH:MM format. I need to create a date and time object for my financial econometrics assignment.

First I paste two objects together and create a character vector such like following:

        Date  Time    Open    High     Low

1 2017.09.01 00:00 1.19013 1.19017 1.19013   

2 2017.09.01 00:01 1.19015 1.19017 1.19015

However, when I tried to convert "date_time_c" character vector to "POSIXct" format, I used the following code.

DATA<-DAT%>%select(Date,Time,Open,High,Low)%>%

        mutate(Date_Time=as.POSIXct(paste(DATA$Date, DATA$Time), format="%YYYY.%mm.%dd %H:%M"))

but as a result, I am receiving "null" values when checked newly created "Date_Time" object

> head(DATA$Date_Time)

[1] NA NA NA NA NA NA

Should I first cast my character vector integers?? I am not sure..

Can anyone help me on this error

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Answer 1

You can also use the lubridate package (part of the Tidyverse) that has functions to convert strings to date or date-time objects using the functions like ymd_hm().

library(tidyverse)
library(lubridate)

df <- tribble(~Date,  ~Time,  ~Open,  ~High,  ~Low,
"2017.09.01", "00:00", "1.19013", "1.19017", "1.19013",   
"2017.09.01", "00:01", "1.19015", "1.19017", "1.19015")

df %>% mutate(Date.Time = ymd_hm(paste(Date, Time, sep=" ")))

which produces

# A tibble: 2 x 6
        Date  Time    Open    High     Low           Date.Time
       <chr> <chr>   <chr>   <chr>   <chr>              <dttm>
1 2017.09.01 00:00 1.19013 1.19017 1.19013 2017-09-01 00:00:00
2 2017.09.01 00:01 1.19015 1.19017 1.19015 2017-09-01 00:01:00

Creating a date/time object by two string objects

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