use strict;
use warnings;
use JSON;
use Data::Dumper;

$_ = '{"temp":75.50,"tmode":2,"fmode":0,"override":0,"hold":0,"t_cool":75.00,"tstate":0,"fstate":0,"time":{"day":4,"hour":13,"minute":49},"t_type_post":0}';

print Dumper decode_json ($_);