If my math is correct, we have to mark these dates on the calendar:
18 March - After Indian Wells - If Nole is the #1, he ties Federer for the oldest #1 at 36 years, 10 months and 10 days.
01 April - After Miami - If Nole is the #1, he become the oldest #1 at 36 years, 10 months and 24 days...