Writing Height and Time in a Manuscript
Question: When describing a character's height in a manuscript should it be written in words or can numbers be used?
Example: 5" 10" or five feet ten inches.
The same question for time, 1:00 or one o'clock?
Answer: Using numerals rather than words is more common in nonfiction, where accurate facts and figures are more important. In fiction, the standard is to use words, with some exceptions.
Sometimes numerals are used when it would be unwieldy to use words, such as with large precise numbers. For instance, you would write "five million troops" because it's a nice round number, and the reader knows the character/narrator is just giving an approximation. But if it is important to give an exact number, such as "5,384,238," you would use numbers. Writing that out in words would be too unwieldy.
It also makes a difference if your character or narrator has a reason for being precise.
In conversation, a character might say to someone "I'll be there by two o'clock" or "around two," knowing that they won't be held to that exact time. On the other hand, a character might say, "the robbery will take place at 2:53 p.m." when precise timing matters.
You would also be more likely to use numbers if your story is being narrated to some extent in the style of a detective, reporter, or scientist's report. For instance, "Tuesday, March 3rd, 10:15 p.m. I was staked out in front of City Hall..."
Unless the narrator or character has a strong reason to make a precise measurement of someone's height or an exact note of the time, it is better to write "five-foot ten" or "one o'clock."
For the same reasons, in fiction you will generally write "percent" rather than "%," "dollars" rather than "$," and "inches" rather than inverted commas.