Time manipulation libraries?

My question would be, is there a good time manipulation library in erlang for:

  • convert date time (rfc) between timezones,
  • adding duration to date time (rfc),
  • calculating daylight saving properly for different timezones

Perhaps this can be a starting point:

Thanks!
I’m wondering if it wouldn’t be a good idea to include some built-in date-time manipulation module in erlang OTP. I know there is a calendar library, but it that lacks some usefull date time manupulation functions.

We’ve been using qdate for many years.

qdate - Simple Date and Timezone handling for Erlang