Nature’s alarm clocks

“Need to buy batteries for the wall clocks,” I thought.
I get up at four in the morning. My phone alarm would wake me up. Thereafter, I tracked the day using the wall clocks.
My grandfather could tell the time by watching the shadows the sun cast. I wondered if that would work for me.
After all, I was living in the same house.
I began observing the day as it unfolded.
I heard the frogs croaking in the pond behind my house as I woke up.
Birds would start chirping around 5.15.
The outlines of the coconut trees would be visible against the gray morning sky by 5.30.
I checked and rechecked over a few days and found that nature’s timekeepers were spot-on every day.
“Maybe I can delay buying the batteries for some time!” I thought.