Time and the First Derivative, Starting with The End in Mind

Time has always been the first derivative.  Time is the flow of space.  Space has mass as such time is kg/s.  The trick here is to realize that time as a unit of measure must be expressed consistently at a particular time speed. In the expression kg/s, seconds is defined at standard time speed c, at time speed v, second is defined as c.s/v.  The factor c/v adjusts for the fact that a given second is longer at speed less than normal time speed c>v and is shorter proportionally at speed greater, c<v.  At c=v, at our present level of existence, is what we define the length of a second is.  c is the normal time speed at a given density of space.  Space has mass, it has density and has an associated terminal velocity, photon terminal velocity in free space is the speed of light.  That speed however changes with the density of space.  Is time speed the speed of light?