Для этого можно использовать 3 разных таймера:
Timer timer1 = new Timer { Interval = 10000, Enabled = True };
Timer timer2 = new Timer { Interval = 300000, Enabled = True };
Timer timer3 = new Timer { Interval = 3600000, Enabled = True };
timer1.Tick += (s,e) => { Your code 10 Sec };
timer2.Tick += (s,e) => { Your code 5 Min };
timer3.Tick += (s,e) => { Your code 1 Hour };
или только один таймер:
int repeat = 0;
Timer timer = new Timer { Interval = 10000, Enabled = True };
timer.Tick += (s, e) =>
{
//Do your 10 second code every time
if(repeat%30==0)
{
//you every 5 minute code
}
if(repeat%360==0)
{
//you every 1 hour code
}
repeat++;
}