-- Return an item that represents a time value.  The item is a
-- list with items that depend on the system.
-- The item can be passed to `reltimestr()` to convert it to a
-- string or `reltimefloat()` to convert to a Float.
-- 
-- Without an argument it returns the current "relative time", an
-- implementation-defined value meaningful only when used as an
-- argument to `reltime()`, `reltimestr()` and `reltimefloat()`.
-- 
-- With one argument it returns the time passed since the time
-- specified in the argument.
-- With two arguments it returns the time passed between {start}
-- and {end}.
-- 
-- The {start} and {end} arguments must be values returned by
-- reltime().  Returns zero on error.
-- 
-- Can also be used as a `method`: 
-- ```vim
--   GetStart()->reltime()
-- ```
-- Note: `localtime()` returns the current (non-relative) time.
--- @param start? any[]
--- @param end_? any[]
--- @return any[]
function vim.fn.reltime(start, end_) end