Simplify the following text for a Grade 7 native English-speaking person.
Original: These templates ( ' and ' ) return a date , or date-time , duplicated in a hidden ISO date format , which degrades gracefully when CSS is not available .
Simplified: It also include the same date ( and time ) duplicated in a hidden ( by CSS ) ISO date format , for use in microformats . This hidden date degrades gracefully when CSS is not available .