1.2dev: : Use `iso8601` format to avoid `ValueError` for year < 1900
1.2dev: : Use `iso8601` format to avoid `ValueError` for year < 1900

This is a merge of [14810] from 1.0-stable.

Refs #12489.


git-svn-id: 0d96b0c1a6983ccc08b3732614f4d6bfcf9cbb42@14811 af82e41b-90c4-0310-8c96-b1721e28e2e2

rbaumg/trac,rbaumg/trac,rbaumg/trac,rbaumg/trac