Ivy supports resolving timestamped snapshots, but with the following limitation: the specified pattern on your ibiblio resolver must end with:
[organisation]/[module]/[revision]/[artifact]-[revision](-[classifier]).[ext]
This is not the case in your setup, so Ivy won’t try to find your timestamped snapshot. Updating your pattern to this one should solve your problem; update the definition of your archiva-snapshots repository to:
<ibiblio name="archiva-snapshots"
m2compatible="true"
usepoms="true"
pattern="[organisation]/[module]/[revision]/[artifact]-[revision](-[classifier]).[ext]"
root="http://host:port/archiva/repository/snapshots"/>
Remark: mind the ‘s’ in [organisation] instead of the ‘z’.
Maarten