I2C LCD Screen, Arduino Freezing after 12-32 hours

Peter_n:
Slower I2C, or lower pullup resistor, or an other cable.
What do you use now for pullup resistors for SDA and SCL ?

I do not currently use pull up resistors on SDA and SCL, my understanding was that the wire library used built in ones.
My RTC may also have some,.. but I didn't purposely use any.

What should I be using?
Thank you,
Whiskey