### ** Examples now()
[1] "2025-08-11 17:06:53 UTC"
now("GMT")
[1] "2025-08-11 17:06:53 GMT"
now("")
[1] "2025-08-11 17:06:53 UTC"
now() == now() # would be TRUE if computer processed both at the same instant
[1] FALSE
now() < now() # TRUE
[1] TRUE
now() > now() # FALSE
[1] FALSE
today()
[1] "2025-08-11"
today("GMT")
[1] "2025-08-11"
today() == today("GMT") # not always true
[1] TRUE
today() < as.Date("2999-01-01") # TRUE (so far)
[1] TRUE