Hi,
I'm trying a simple pgsql program with PQexecPrepared and have a few questions. 
I have seen the example but didn't find the answer there. googled too.
http://www.postgresql.org/docs/9.2/static/libpq-example.html

Q1. what format is date set in ? what is the length ?

Q2.Q2.what is the type and length of bit wise fields

Q3. how to convert seconds since epoch to date

Q4. is int passable as time?

Q5. the paramValsVec_ is char* const char[] . Can we type cast int to char* and pass in ? and set type to INT4OID?

Below is some pseudo code to put above questions in perspective.
>>. table 
CREATE TABLE t1
(curdate                 date,
str1                     varchar(19),
tm_new                  timestamptz,
count                       int);
>>> c++ code PGconn* pgconn; // connected

char * UpsertStmt_= "INSERT INTO t1 values( $1, $2, $3, $4)";

 int result=0;
 PGresult* pgres = PQprepare (pgconn, "stmtname", UpsertStmt_, 4, NULL);
  int result = PQresultStatus(pgres);
  PQclear(pgres_);

struct mydata
{
int curtime;
char str1[32];
int mycount;
 intmybitfield : 3;

},
mydata myvar;
myvar.curtime = time(NULL)

strcpy(myvar.str1, hello);

myvar.mycount = 2;
myvar.mybitfield = 2;

  // set helper vars
 paramLenVec_[0]  = 8;// Q1. what format is date set in ? what is the length
 paramLenVec_[1]  = strlen(str1);
 paramLenVec_[2]  = sizeof(int);  // type = INT4OID, sizeof (int)
 paramLenVec_[3]  = sizeof(int);// Q2.what is the type and length of bit wise fields

  paramValsVec_[0]  = (char*)&myvar.curtime; // Q3. how to convert to date
  paramValsVec_[1]  = myvar.str1;
  paramValsVec_[2]  = &myvar.curtime; // Q4. is int passable as time
  paramValsVec_[3]  = (char*)&myvar.mycount; // Q5. 
PQexecPrepared (pgconn, "stmtname", 4, 
   paramValsVec_,
   paramLenVec_,
  NULL, 0
);