View Compilation Error

0_0_4737063_5178.cpp: In function `db calTime(int, int, db)':
0_0_4737063_5178.cpp:37: error: `tm' undeclared (first use this function)
0_0_4737063_5178.cpp:37: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4737063_5178.cpp: In function `int main()':
0_0_4737063_5178.cpp:61: error: `tm' undeclared (first use this function)