Epoch and Millisencond about elm-time HOT 1 CLOSED

I believe you might be under two misconceptions:

1. DateTime.millisecond simply gets the millisecond fraction of the time between seconds.
   • In other words:

     > import Time.DateTime exposing (..)
     > epoch |> addSeconds 2 |> addMilliseconds 123 |> millisecond
     123 : Int

   • So it makes sense that epoch yields millisecond as zero as well as all the other time components.
2. You may be thinking of the "timestamp" which is also zero at the time of the epoch. This is discussed further below.

epoch is not an endpoint in time; it is an arbitrary midpoint:

0 is the midpoint of the "Unix time" which also happens to be the start of 1970:

> epoch |> toTimestamp
0 : Time.Time
> epoch |> toISO8601
"1970-01-01T00:00:00.000Z" : String

Positive timestamps are more recent:

> epoch |> addYears 1 |> toTimestamp |> Debug.log "timestamp" |> fromTimestamp |> toISO8601
timestamp: 31536000000
"1971-01-01T00:00:00.000Z"
    : String

And negative timestamps are further back in the past:

> epoch |> addYears -1 |> toTimestamp |> Debug.log "timestamp" |> fromTimestamp |> toISO8601
timestamp: -31536000000
"1969-01-01T00:00:00.000Z"
    : String

Hope these are the answers you were looking for!

from elm-time.