Takes one parameter, the year-number. Prefix it with a minus sign for BC.
The box width shrinks nearly 6% for smaller year-number sizes.

Example for "{{Year nav|2013}}" at right:
Millennium: 3rd millennium
Centuries: 20th century21st century22nd century
Decades: 1980s  1990s  2000s  – 2010s –  2020s  2030s  2040s
Years: 2010 2011 201220132014 2015 2016
Example for "{{Year nav|100}}" at right:
Millennium: 1st millennium
Centuries: 1st century BC1st century2nd century
Decades: 70s  80s  90s  – 100s –  110s  120s  130s
Years: 97 98 99100101 102 103
Example for "{{Year nav|14}}" at right:
Millennium: 1st millennium
Centuries: 1st century BC1st century2nd century
Decades: 10s BC  0s BC  0s  – 10s –  20s  30s  40s
Years: 11 12 131415 16 17
Example for "{{Year nav|-114}}" at right:
Millennium: 1st millennium BC
Centuries: 3rd century BC2nd century BC1st century BC
Decades: 140s BC  130s BC  120s BC  – 110s BC –  100s BC  90s BC  80s BC
Years: 117 BC 116 BC 115 BC114 BC113 BC 112 BC 111 BC