All measurements taken with display initialized to "bA9876543210".
Vcc= 3.51V.
2.12uA Count switching between 00 and 01 at 2hz. 2.00uA with ~INT unplugged so no interrupts or display updates, display at 01.
0.39uA just RTC with 2.hz ~INT and direct switching mode.
2.05uA with RTC connected 1.67uA without RTC connected
1.23uA RTC at default power up with clkout 32768 0.17uA RTC with clkout disabled, backup disabled 0.18uA RTC with direct switchover mode enabled
-- So direct switchover mode is very power cheap, so probably not worth adding a diode to save 0.01uA.
0.40uA RTC with 2Hz periodic timer off the 4096Hz base 0.34uA RTC with 1/64Hz periodic timer off the 64Hz base. 0.34uA RTC with 1/4096Hz periodic time off the 1Hz base.
--So the periodic timer uses ~0.16uA even on low base frequencies. Wish I had know that before!
0.18uA RTC with 1Hz square wave on clkout
--So clkout is the efficient way to go. :/