Key Value
seconds Seconds
minutes Minutes
hours Hours
mday Day of the month
wday Day of the week, numeric (Sunday is 0, Saturday is 6)
mon Month, numeric
year Year, numeric (4 digits)
yday Day of the year, numeric (e.g., 299)
weekday Day of the week, textual, full (e.g., "Friday")
month Month, textual, full (e.g., "January")
0 Seconds since epoch (what time( ) returns)