Centuries: 1st century BC - 1st century - 2nd century
Decades: 10s BC - 0s - 10s - 20s - 30s - 40s - 50s - 60s - 70s - 80s - 90s
40 41 42 43 44 45 46 47 48 49
Sometimes the '40s is used as shorthand for the 1940s, the 1840s, or other such decades in various centuries
