[EN/DE/ES/...] 'Part of Day' rule coerces timespans

Some time spans are incorrectly interpreted, yielding values that seem caused by a defaulting rule. Parsing is correct, but when building the final Entitys for some reason the time span from and to are incorrect.

All of these report the correct time spans:

vormittags von 3 bis 11 Uhr
vormittags von 4 bis 11 Uhr
...
vormittags von 10 bis 11 Uhr

If the lower bound is 1 or 2 the lower bound is (incorrectly) set to 03:00.

On the other side, if the upper bound is 12 or greater then the time span defaults to 03:00 to 12:00 consistently. I tracked down the issue to the rule time-of-day (latent):

https://github.com/facebook/duckling/blob/d8888e2ff842c4dacd570989570c101cf7b43153/Duckling/Time/DE/Rules.hs#L959

As far as I understand, 'latent' means that there's some ambiguity. For example, the number 7 could mean several things depending on the context.

Lets change this rule and use the check n < 13 like in the EN version:

https://github.com/facebook/duckling/blob/d8888e2ff842c4dacd570989570c101cf7b43153/Duckling/Time/EN/Rules.hs#L577

This will no longer break the lower bound when the upper bound is 12. Nevertheless, the issue remains for the upper bound: values 12 ... as upper bound result in ranges 03:00 to 12:00 consistently. Do these values ring any bell? some kind of defaulting rule?

Start in Duckling/Time/DE/Rules.hs at the time-of-day (latent) rule and compare it with the corresponding rule in Duckling/Time/EN/Rules.hs. Reproduce the German vormittags von 1 bis 11 Uhr and vormittags von 3 bis 12 Uhr cases, then trace entity construction to identify why the bounds become 03:00 or 12:00. Done means the reported lower and upper time bounds are preserved correctly.