Use https://commons.wikimedia.org/wiki/Special:UploadWizard . Try uploading any photo. Write Screenshot 2019-01-01 ab as your filename. A warning pops up. The (more info) button looks like a link but is just a decoy. The button is part of class="oo-ui-labelElement-label" .
(Fun fact: been reported many times
https://commons.wikimedia.org/wiki/Commons:Village_pump/Archive/2018/01#Filename_blokkage
https://commons.wikimedia.org/wiki/Commons:Help_desk/Archive/2018/12#Beginner_uploader_to_wikimedia,_question_about_error_messages
https://commons.wikimedia.org/wiki/User_talk:Wargaz#Middle_(Naming_convention) )