# How to Use difftime in R to Calculate Time Differences

You can use the difftime() function to calculate the time difference between two dates or datetimes in R.

This function uses the following basic syntax:

```difftime(time1, time2, units="days")
```

where:

• time1, time2: The two dates or datetimes
• units: The units to use for time difference (default is “days”, but other options include “secs”, “mins”, “hours”, and “weeks”)

The following examples show how to use the difftime() function in different scenarios.

### Example 1: Use difftime() to Calculate Time Difference in Various Units

The following code shows how to use the difftime() function to calculate the time difference between two datetimes using various units:

```#define two datetimes
first <- "2022-08-20 08:15:22"
second <- "2022-01-01 20:04:48"

#calculate time difference in days
difftime(first, second)

Time difference of 230.5073 days

#calculate time difference in seconds
difftime(first, second, units="secs")

Time difference of 19915834 secs

#calculate time difference in minutes
difftime(first, second, units="mins")

Time difference of 331930.6 mins

#calculate time difference in hours
difftime(first, second, units="hours")

Time difference of 5532.176 hours

#calculate time difference in weeks
difftime(first, second, units="weeks")

Time difference of 32.92962 weeks
```

By using the units argument, we can calculate the time difference between the two datetimes in different units.

### Example 2: Calculate Time Difference in HH:MM:SS Format

We can also use the as_hms() function from the hms library to calculate the time difference between two datetimes, formatted as HH:MM:SS.

```library(hms)

#define two datetimes
first <- "2022-01-01 20:15:22"
second <- "2022-01-01 08:04:48"

#calculate difference between datetimes in hours, minutes, seconds
as_hms(difftime(first, second))

12:10:34```

The output shows the time difference between the two datetimes, formatted in terms of hours, minutes, and seconds.

In this scenario, the difference between the two times is 12 hours, 10 minutes, and 34 seconds.