Convert decimal day to HH:MM

Question

I have a vector of decimal numbers, which represent \'decimal day\', the fraction of a day. I want to convert it into HH:MM format using R.

For example, the number

Answer 1

One option with data.table:

> library(data.table)
> structure(as.integer(0.4305556*60*60*24), class="ITime")
[1] "10:20:00"

We convert from day fraction to seconds since midnight; coerce to integer; and apply ITime class. (ITime works with integer-stored seconds since midnight.)

Other resources:

• @GaborGrothendieck re chron package and link to his R News article with Thomas Petzoldt about converting from Excel in particular Converting a time decimal/fraction representing days to its actual time in R?
• @JorisChau re RStudio's hms package how to convert excel internal coding for hours to hours in R?