"Illegal instant due to time zone offset transition"

[marcushg]

Hi, first of all thanks for saving us the trouble to deal with random date generation.

From time to time we run into an 'Illegal instant due to time zone offset transition' exception due to generating a date which happens to "not exist".

Should be easy to reproduce like this:

import com.fortysevendeg.scalacheck.datetime.joda.ArbitraryJoda._
import org.scalacheck.Arbitrary.arbitrary
import org.joda.time.DateTime

(1 to 10000).map(_ => arbitrary[DateTime].sample)

sometimes results in e.g.

org.joda.time.IllegalInstantException: Illegal instant due to time zone offset transition (daylight savings time 'gap'): 173829578-03-26T02:52:52.521 (Europe/Berlin)
  at org.joda.time.chrono.ZonedChronology.localToUTC(ZonedChronology.java:157)
  at org.joda.time.chrono.ZonedChronology.getDateTimeMillis(ZonedChronology.java:122)
  at org.joda.time.chrono.AssembledChronology.getDateTimeMillis(AssembledChronology.java:133)
  at org.joda.time.base.BaseDateTime.<init>(BaseDateTime.java:257)
  at org.joda.time.base.BaseDateTime.<init>(BaseDateTime.java:198)
  at org.joda.time.DateTime.<init>(DateTime.java:476)
[....]

The link above has more details on the cause and some ideas on mitigating it, though I am not sure what steps would be appropriate in this case to still have completely random dates. Thanks!

[noelmarkham]

Hi Marcus,

Thanks for this, I'll take a look at reproducing this and will let you know ASAP. Great to see that it's been useful so far.

Cheers
Noel

[noelmarkham]

Hi @marcushg

I've published a new SNAPSHOT containing a fix for this. I expect to publish a release in the next day or two.

Find it at https://oss.sonatype.org/content/repositories/snapshots/com/fortysevendeg/scalacheck-datetime_2.12/0.2.1-SNAPSHOT/scalacheck-datetime_2.12-0.2.1-SNAPSHOT.jar

It's also published for Scala 2.10 and 2.11.

Any issues please let me know, and please keep raising issues if this library is useful.

Cheers
Noel

[marcushg]

Thanks alot @noelmarkham! Tried the snapshot version quickly and it works as expected (i.e. I can't reproduce my error) 👍