You really want to use a time library built by physicists,
which is why I've always appreciated the Go standard
"time" library by Russ Cox and Rob Pike.
In contrast, timestamp support in other languages, like R, is based on
the C standard lib, which can be painful.
I've actually built R libraries that entirely use the Go
standard time library in preference
to the R builtin timestamp handling, in order to use Go's its vastly
better time package.
On top of "time", one usually needs date and calendar support.
I've open sourced my date, calendar, and timestamp handling
library, called "zetm" which has been used in extensive
time-series processing production code.
Enjoy.
Jason