How am I supposed to get the water chip when time passes by so fast??? All I did was exit the cave, fight a scorpion, meet some people in armor in the desert, and go to Shady Sands.
If you don't make any unnecessary round-trips you should have plenty of time to find and return the water chip. After that the timer to finish the game is about 13 years so practilly unlimited.
^ Not sure what happens if you don't get the water chip, but if the Master is still alive/MMB vats still operating after 500 days/13 years (depending on what patch you're playing on I think), you get a creepy game-over cutscene where the mutants invade Vault 13 and kill everyone. Maybe the same thing happens if you don't retrieve the chip?