1st: New Years Day (Gregorian calendar) - all night parties and celebrations including fireworks displays in cities and locations worldwide, but especially Western ones
Late January or early February: Chinese New Year, celebrated in China, Singapore and anywhere where there are large concentrations of Chinese
26th: Australia Day in Australia - a public holiday commemorating the arrival of the convict First Fleet in 1788 and the establishment of both the city of Sydney and the colony of New South Wales, celebrated in grand style in Sydney (especially) and country-wide, with public firework displays and home barbeques
Epiphany day is a Christian feast intended to celebrate the incarnation of God in Jesus Christ. National Bank holiday and the official end of the Christmas season in Spain.