Having Rosh Chodesh Kisslev on Sunday & Monday, occurs approximately 11 times in 100 years.
Please note, that although this last week in marCheshvon [as well as every date since this past Adar] is the 1st time this early since 1899, yet by the time we hit Kisslev next week, it shall only be the 1st time that this early since 1994.