Vladimir, I thought that TimestampString IS the appropriate type :D (knowledge based on Rexbuilder code, where TimestampString is being created as RexLiteral).
My problem is that I don't see what is the scope of TimestampString, DateString, etc in Calcite. Does it span to Rel/Rex tree? Or it should not? This is why I've created two different patches :( Any help with the responsibility of TimestampString appreciated. Without it - bug is still there and I could create lots of other mishit patches.
