Possible Clues:

• That's bound to be one in four in time
• It's bound to be like that twenty-five percent of the time
• Time to 8 across a little longer than most
• It contains an extra day
• It's bound to be one in four then
• It's bound to come fourth
• Time for the high jump contest?
• But it's not the only twelvemonth containing spring
• 2004, e.g.
• When the lady may traditionally propose