I don't think it works that way. You can move the match within the top eleven day. It does required 24 hours notice to move the match to an earlier time, but it doesn't require any notice to move it to a later time.
I attempted to change a match that was at 15:45 for me at around 7:00. I was unable to do so since there were no suitable times available. They top eleven day ends at around 21:30 for me, so the only reason I can think of why I couldn't change the time was because my opponent had a match later in the evening and it would have violated the 3 hour rule.