You won't get much life out of that 9V battery. A typical 9V battery is rated for about 150mAh, you are drawing a significant amount of current from the battery so a rough guess would be somewhere between 12 and 24 hours. If you are trying to power the relay with the 9V battery then you will get even fewer hours. You can get a longer run time out of a series of AA type batteries or larger. AA batteries could last a few days to maybe a few weeks, if you go up to D cells then you can probably get close to a month or more.
These are just rough guesses, I haven't actually calculated for any exact numbers.