Hello. I am new to the forum and to the actual building of electronics itself. I am trying to put together a timer which will be off for 8 hours and on for 29 seconds. Odd i know. I have pretty much figured out the design i think and the calculations for the resistors and capacitors to give me my desired time. My question at this time before I buy my materials is that I read that electrolytic capacitors values are not entirely accurate and in an 8 hour span it could increase the time by as much as 1 or so hours. Is there another type of capacitor that could be used to more accurately reach my goal? Thank you for your help.