hms R Package

The hms package provides a class for storing durations or time-of-day values, displayed in hh:mm:ss format. It is designed to simplify data exchange with databases and spreadsheets.

Key features:

• Internal Storage: Values are stored as a numeric vector representing the number of seconds since midnight.
• Flexibility: Supports values that exceed the 24-hour boundary or are negative.
• Precision: By default, displays fractional seconds up to a microsecond.
• Integration: Based on the difftime class and can be used as a column in a data frame.

Objects of the hms class (and the underlying difftime class) are stored as the number of seconds since 00:00:00.

To convert an hms object to its numeric underlying value, use as.numeric(). To convert a numeric value (seconds since midnight) back into an hms object, use as_hms().

times <- parse_hms(c("00:00:00.25", "00:00:01", "00:01:30", "01:00:00"))

# Convert to numeric (seconds since midnight)
times_num <- as.numeric(times)
# [1] 0.25 1.00 90.00 3600.00

# Convert numeric back to hms
as_hms(times_num)
#> 00:00:00.25
#> 00:00:01.00
#> 00:01:30.00
#> 01:00:00.00

You can install hms as part of the tidyverse suite, as a standalone package from CRAN, or via GitHub using pak.

# Install the whole tidyverse:
install.packages("tidyverse")

# Install just hms:
install.packages("hms")

# Install the development version from GitHub:
# install.packages("pak")
pak::pak("tidyverse/hms")

You can create hms objects using explicit time components, parsing strings, or coercing from POSIXt objects. The class can also be used directly within data frames.

library(hms)

# Construct from hours, minutes, and seconds
hms(56, 34, 12)
#> 12:34:56

# Coerce from POSIXt (e.g., Sys.time())
as_hms(Sys.time())
#> 10:27:38.905625

# Parse from a string
parse_hms("12:34:56")
#> 12:34:56

# Coerce to POSIXct
as.POSIXct(hms(1))
#> [1] "1970-01-01 00:00:01 UTC"

# Use as a column in a data frame
data.frame(hours = 1:3, hms = hms(hours = 1:3))
#>   hours      hms
#> 1     1 01:00:00
#> 2     2 02:00:00
#> 3     3 03:00:00