Thanks Alexander for your answer. I opened an issue in `time` repository: https://github.com/haskell/time/issues/104 It seems it is intended behaviour, but I think it is inconsistent and it makes difficult to parse from a string when you don't know beforehand the format it has. In the issue link there is the developed version of my answer... :) Marc Busqué http://waiting-for-dev.github.io/about/ On Fri, 14 Sep 2018, Alexander V Vershilov wrote:

Hi Marc,

The best way of answering such questions is to check the source code. Hackage provides a nice way of doing that - click on 'Source' near the instance that you are interested in:

https://hackage.haskell.org/package/time-1.6.0.1/docs/Data-Time-Format.html#...

And you'll see the implementation

```

instance ParseTime LocalTime where buildTime l xs = LocalTime <$> (buildTime l xs) <*> (buildTime l xs) ```

That builds time from `Day` and `TimeOfDay` passing your parse string to each of those. Then you can check ParseTime instance of Day:

https://hackage.haskell.org/package/time-1.6.0.1/docs/src/Data.Time.Format.P...

I'm not providing it here, as it's quite big, but the main point is that `s` is ignored so in that case Day appear to be:

``` rest (YearMonth m:_) = let d = safeLast 1 [x | MonthDay x <- cs] in fromGregorianValid y m d ``` with y=m=d=1

if you continue the process for TimeOfDay you'll find that `s` is ignored there as well, and `midnight = TimeOfDay 0 0 0` is returned in that case.

So it appeared that LocalTime consists of the components that ignore your parse string and return default value instead.

I don't know if that is intended behaviour or not, but for me it makes more sense to parse to UTCTime/POSIXTime and then convert into LocalTime, in case if you get seconds as input.

Hope that helps.

On Thu, 6 Sep 2018 at 13:42, Marc Busqué wrote:

...

In GHCi

``` :m +Data.Time parseTimeM True defaultTimeLocale "%s" "1535684406" :: Maybe UTCTime -- => Just 2018-08-31 03:00:06 UTC parseTimeM True defaultTimeLocale "%s" "1535684406" :: Maybe LocalTime -- => Just 1970-01-01 00:00:00 ```

Why? ¯\(°_o)/¯

Marc Busqué http://waiting-for-dev.github.io/about/_____________________________________... Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

-- Alexander