I recently extracted an IFCzip file after renaming its extension from .ifczip to .zip and the timestamp differs exactly by a month. I think built-in zipper engine fails when adding correct date to the zipped result. Please fix it.
We use ifczips on a project where have to make a Navisworks .NWD also, and navis can't eat IFCzips.
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A previous post mention this bug:
.IFC gets wrong date after unzipping .ifczip - Graphisoft Community
Operating system used: Windows 4030 HUN FULL