def fib(n, cache = {0: 0, 1: 1}):
if n not in cache:
cache[n] = fib(n-1) + fib(n-2)
return cache[n] now() {
cal -3
echo
echo -n "Local: "
date --rfc-3339=s
echo -n "UTC: "
date -u --rfc-3339=s
echo -n "New York "
TZ='America/New_York' date --rfc-3339=s
echo -n "London: "
TZ='Europe/London' date --rfc-3339=s
echo -n "New Zealand: "
TZ='Pacific/Auckland' date --rfc-3339=s
}