cfunction
src/core/os.c on line 1849 , column 1
(os/strftime fmt &opt time local )
Format the given time as a string , or the current time if `time` is
not given. The time is formatted according to the same rules as the
ISO C89 function strftime (). The time is formatted in UTC unless
`local` is truthy , in which case the date is formatted for the
local timezone.