Hi!
I want to make a schedule a job for sending emails or texting messages.
And I found rihanna.

But before do that, I need a more understanding of DateTime..
I get an datetime input from customer in this format
date = “2019-09-25”
time = “16:00”

1. How can I format this input to DateTime format? I tried.

  def build_datetime(date, time) do
    with {:ok, datetime, 0} <- DateTime.from_iso8601("#{date} #{time}:00"),
      do: datetime
  end

But got an error

{:error, :missing_offset}

2. I want to check user’s datetime is in future( 30 mins future from now on). So I would do this..

def schedule_datetime_is_future?(schedule_datetime) do
  DateTime.diff(schedule_datetime, DateTime.utc_now) > 30 * 60
end

3. in rihanna docs says

Rihanna.schedule(
  {IO, :puts, ["Hello"]},
  at: DateTime.from_naive!(~N[2018-07-01 12:00:00], "Etc/UTC")
)

So before I have to compare datetime, should I convert datetime to UTC datetime?
It works in different timezone?