Code:
//godina dtpOd
String aa = dtpOd.Value.Date.Year.ToString();
int aaInt;
aaInt = Convert.ToInt32(aa);
aaInt = int.Parse(aa);
//godina dtpDo
String bb = dtpDo.Value.Date.Year.ToString();
int bbInt;
bbInt = Convert.ToInt32(bb);
bbInt = int.Parse(bb);
//random godine
Random r1 = new Random();
int randomYear1 = r1.Next(aaInt, bbInt);
Random r2 = new Random();
int randomYear2 = r2.Next(randomYear1, bbInt);
//random mesec i dan za dtpOd
int randomMonthNr1 = r1.Next(1, 13);
int maxDayNr1 = DateTime.DaysInMonth(randomYear1, randomMonthNr1);
int randomDayNr1 = r1.Next(1, (maxDayNr1 + 1));
//random mesec i dan za dtpDo
int randomMonthNr2 = r2.Next(1, 13);
int maxDayNr2 = DateTime.DaysInMonth(randomYear2, randomMonthNr2);
int randomDayNr2 = r2.Next(1, (maxDayNr2 + 1));
//random korisnici i dogadjaji
comboBox1.SelectedIndex = (new Random()).Next(comboBox1.Items.Count);
comboBox2.SelectedIndex = (new Random()).Next(comboBox2.Items.Count);
//random vreme
Random sat1 = new Random();
Random minut1 = new Random();
Random sekund1 = new Random();
int randomSati1 = sat1.Next(0, 24);
int randomMinuti1 = minut1.Next(0, 59);
int randomSekunde1 = sekund1.Next(0, 59);
Random sat2 = new Random();
Random minut2 = new Random();
Random sekund2 = new Random();
int randomSati2 = sat2.Next(randomSati1, 24);
int randomMinuti2 = minut2.Next(randomMinuti1, 59);
int a = 1;
int randomSekunde2 = sekund2.Next(randomSekunde1 + a, 59); //randomSekunde1 + 1, 59 ; ovo +1 da bude razlike u vremenima ako se desi preklapanje
//upis stringova za random unos
string s1 = "" + maxDayNr1 + "." + randomMonthNr1 + "." + randomYear1 + " " + randomSati1 + ":" + randomMinuti1 + ":" + randomSekunde1;
string s2 = "" + maxDayNr2 + "." + randomMonthNr2 + "." + randomYear2 + " " + randomSati2 + ":" + randomMinuti2 + ":" + randomSekunde2;
string tekstKomande = "insert into Tomislav (Korisnik, Dogadjaj, DatumOd, DatumDo) values('" + this.comboBox1.SelectedItem + "','" + this.comboBox2.SelectedItem + "','" + s1 + "','" + s2 + "') ;";
//godina dtpOd
String aa = dtpOd.Value.Date.Year.ToString();
int aaInt;
aaInt = Convert.ToInt32(aa);
aaInt = int.Parse(aa);
//godina dtpDo
String bb = dtpDo.Value.Date.Year.ToString();
int bbInt;
bbInt = Convert.ToInt32(bb);
bbInt = int.Parse(bb);
//random godine
Random r1 = new Random();
int randomYear1 = r1.Next(aaInt, bbInt);
Random r2 = new Random();
int randomYear2 = r2.Next(randomYear1, bbInt);
//random mesec i dan za dtpOd
int randomMonthNr1 = r1.Next(1, 13);
int maxDayNr1 = DateTime.DaysInMonth(randomYear1, randomMonthNr1);
int randomDayNr1 = r1.Next(1, (maxDayNr1 + 1));
//random mesec i dan za dtpDo
int randomMonthNr2 = r2.Next(1, 13);
int maxDayNr2 = DateTime.DaysInMonth(randomYear2, randomMonthNr2);
int randomDayNr2 = r2.Next(1, (maxDayNr2 + 1));
//random korisnici i dogadjaji
comboBox1.SelectedIndex = (new Random()).Next(comboBox1.Items.Count);
comboBox2.SelectedIndex = (new Random()).Next(comboBox2.Items.Count);
//random vreme
Random sat1 = new Random();
Random minut1 = new Random();
Random sekund1 = new Random();
int randomSati1 = sat1.Next(0, 24);
int randomMinuti1 = minut1.Next(0, 59);
int randomSekunde1 = sekund1.Next(0, 59);
Random sat2 = new Random();
Random minut2 = new Random();
Random sekund2 = new Random();
int randomSati2 = sat2.Next(randomSati1, 24);
int randomMinuti2 = minut2.Next(randomMinuti1, 59);
int a = 1;
int randomSekunde2 = sekund2.Next(randomSekunde1 + a, 59); //randomSekunde1 + 1, 59 ; ovo +1 da bude razlike u vremenima ako se desi preklapanje
//upis stringova za random unos
string s1 = "" + maxDayNr1 + "." + randomMonthNr1 + "." + randomYear1 + " " + randomSati1 + ":" + randomMinuti1 + ":" + randomSekunde1;
string s2 = "" + maxDayNr2 + "." + randomMonthNr2 + "." + randomYear2 + " " + randomSati2 + ":" + randomMinuti2 + ":" + randomSekunde2;
string tekstKomande = "insert into Tomislav (Korisnik, Dogadjaj, DatumOd, DatumDo) values('" + this.comboBox1.SelectedItem + "','" + this.comboBox2.SelectedItem + "','" + s1 + "','" + s2 + "') ;";