Time to read a book.
Time to wash dishes.
Time to do this or that. You say things like this every day, all the time. But there was a time when time itself was undefined--no one knew the difference between a minute, an hour, or a day.
Then people started creating tools to measure time. First they used the big stuff around them--the sun, the moon, water. Soon after, using the knowledge they got from their natural time-telling tools,...