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

Try this:

R> format(as.POSIXct(Sys.Date() + 0.8541667), "%H:%M", tz="UTC")
[1] "20:30"
R> 

We start with a date--which can be any date, so we use today--and add your desired fractional day.

We then convert the Date type into a Datetime object.

Finally, we format the hour and minute part of the Datetime object, ensuring that UTC is used for the timezone.