Can't a legislature mandate that the benefits currently available to full-time workers (currently defined as ~40h/wk) are suddenly now available to full-time wo

Can't a legislature mandate that the benefits currently available to full-time workers (currently defined as ~40h/wk) are suddenly now available to full-time workers (newly redefined as 32h/wk) ? No new assertions of power, just a redefinition of a threshold.