The 2σ lower limits of the time interval t−t₀ between a future moment and today, for the wCDM (upper left panel), the IwCDM1 (upper right panel), the IwCDM2 (lower left panel) and the IwCDM3 (lower right panel) model. combined (black solid lines), SALT2 (red dashed lines), and SiFTO (green dash-dotted lines) denote the results given by the SN(combined)+CMB+GC, the SN(SALT2)+CMB+GC, and the SN(SiFTO)+CMB+GC data, respectively. The 2σ lower bound values of t_BR−t₀ given by the three SNLS3 data are also listed on this figure.