❖ Answer ❖
library(lubridate)
ymd("2024-07-01")
dmy("15/08/2023")
ymd_hms("2024-01-15 14:30:45")
mdy_hm("07-13-2024 14:45") # correct
Jihong Zhang*, Ph.D
Educational Statistics and Research Methods (ESRM) Program*
University of Arkansas
August 18, 2025
lubridate
package and print the current date and time using R functions.Date
objects:
"2024-07-01"
"15/08/2023"
(Use the correct format for parsing.)POSIXct
date-time objects:
"2023-12-25 18:30:00"
"07-13-2024 14:45"
(Use the correct format for parsing.)- Read this CSV into R using `read_csv()`.
- Ensure that the `date` column is parsed as a `Date` and the `datetime` column is parsed as a `POSIXct` object.
date
column correctly, assuming it follows the "MM-DD-YYYY"
format.Given the date vector:
"2024-07-12 15:47:23"
, apply:
floor_date()
to round it down to the nearest hour.ceiling_date()
to round it up to the nearest day.round_date()
to round it to the nearest 10-minute interval.library(lubridate)
dt <- ymd_hms("2024-07-12 15:47:23")
# Round down to the nearest hour
floor_dt <- floor_date(dt, unit = "hour")
# Round up to the nearest day
ceiling_dt <- ceiling_date(dt, unit = "day")
# Round to the nearest 10-minute interval
round_dt <- round_date(dt, unit = "10 minutes")
# Print results
floor_dt # "2024-07-12 15:00:00"
ceiling_dt # "2024-07-13 00:00:00"
round_dt # "2024-07-12 15:50:00"
"2025-02-15"
into the following formats using format()
:
"YYYY/MM/DD"
"Month Day, Year"
(e.g., "February 15, 2025"
)"Day-Month-Year"
(e.g., "15-February-2025"
)date <- as.Date("2025-02-15")
# Format as "YYYY/MM/DD"
format_1 <- format(date, "%Y/%m/%d")
# Format as "Month Day, Year"
format_2 <- format(date, "%B %d, %Y")
# Format as "Day-Month-Year"
format_3 <- format(date, "%d-%B-%Y")
# Print results
format_1 # "2025/02/15"
format_2 # "February 15, 2025"
format_3 # "15-February-2025"
"America"
."2024-08-01 12:00:00"
from "UTC"
to:
"America/New_York"
"Europe/London"
"Asia/Tokyo"
"US/Central"
and "Asia/Hong_Kong"
on January 1, 2025.
difftime(units = "hours")
to return time difference between two time# Get the system's current time zone
current_tz <- Sys.timezone()
# List all available time zones containing "America"
america_tzs <- OlsonNames()[grep("America", OlsonNames())]
# Print results
current_tz # Example: "America/Chicago" (varies by system)
america_tzs # Displays all time zones containing "America"
library(lubridate)
# Define the UTC datetime
utc_time <- ymd_hms("2024-08-01 12:00:00", tz = "UTC")
# Convert to different time zones
ny_time <- with_tz(utc_time, "America/New_York")
london_time <- with_tz(utc_time, "Europe/London")
tokyo_time <- with_tz(utc_time, "Asia/Tokyo")
# Print results
ny_time # "2024-08-01 08:00:00 EDT"
london_time # "2024-08-01 13:00:00 BST"
tokyo_time # "2024-08-01 21:00:00 JST"
# Define the datetime in "US/Central"
central_time <- ymd_hms("2025-01-01 00:00:00", tz = "US/Central")
# Convert to "Asia/Hong_Kong"
hk_time <- ymd_hms("2025-01-01 00:00:00", tz = "Asia/Hong_Kong")
# Compute time difference in hours
time_difference <- as.numeric(difftime(hk_time, central_time, units = "hours"))
# Print result
time_difference # 14 (hours)