Historical clue formulations

• Ceilings — 2018-09-15
• High points — 2017-10-20
• Ceilings, informally — 2014-11-21
• Ceilings — 2014-09-12
• Completely uses up, as a credit card, with "out" — 2009-10-26
• Levels off, with "out" — 2001-10-19