“…Many numerical methods have been developed to approximate the solution of differential equations, e.g., [1,11,32,39,[44][45][46][47]. In complex applications it is however still common to use simple methods, such as the constant time step backward Euler [16,71], the midpoint rule [4,7,18,42,48,68], the trapezoid rule [34,49] or, increasingly, the second-order backward difference (BDF2) method [5,17,28,29,59,78,79,83]. It is well known [67] that for linear multistep methods, unfavorable combinations of variable steps can lead to instability.…”