The official calendar of the Republic of the Philippines: an almanac of Philippine commemorations enlivened with illustrations and information. –Manila: Presidential Communications Development and Strategic Planning Office, .
On this day in 1521, Martin Luther was excommunicated by the order of Pope Leo X.
On this day in 1919, Ernest Rutherford succeeded in breaking apart a nitrogen atom and transmuting it into oxygen.
January is National Microinsurance Month (Proclamation No. 1212, s. 2007).