Possible Clues:

• (Sign of day that's) memorably important
• Memorable revolutionary character
• Important, in a way
• Most important, and correspondingly rubricated?
• Blushing landlady is remarkable
• Persued the epistle, by the sound of it, for the important day
• When it's important by day to have studied the correspondence, by the sound of it
• An important day to have perused the missive, by the sound of it
• Like a noteworthy day
• Description of great day for Marxist landlord