Related Clues:

• Type of number
• Neither early nor late
• Before the bell
• According to schedule
• 'Soap,' for one
• Ongoing story
• Welcome words at La Guardia
• Story that's 'to be continued'
• Soap opera, e.g.
• Just when expected
• "Flash Gordon," e.g.
• Not delayed
• 'Buck Rogers,' for one
• Soap opera
• Published in installments