Convert time in seconds to a formatted string hh:mm:ss.ms

Convert time in seconds to a formatted string.lua

function format_time_given_in_sec(num_sec)
	local function add_lead_zero(num)
	return #(num..'') == 1 and '0'..num or num
	end
local hrs = math.modf(num_sec/3600) -- 3600 sec in an hour
local sec = num_sec%3600 -- remainder in sec
local mnt = math.modf(sec/60) -- 60 sec in a min
local sec_ms = sec%60 -- remainder in sec and ms as a decimal part
local dec_places = 10^3
local sec_ms = math.floor(sec_ms * dec_places + 0.5) / dec_places -- round ms down to 3 dec places
local col = ':'
return add_lead_zero(hrs)..col..add_lead_zero(mnt)..col..sec_ms
end