I wasn't sure how to research this without being able to explain what I mean.
When someone says something like "I will have it done by tomorrow", does that phrase mean that they will have it done before tomorrow, or does it mean before tomorrow is over?
Also, how would less-defined times be affected by this? For example, "I'll have it done by tonight"...
The intended timing is indeterminate, which is intentional. The person using such a phrase is leaving a little wiggle room. Generally it means "sometime within the specified period." Compare it with a more precise statement like, "I'll have it done by six o'clock tonight." No wiggle room here. This statement means, "no later than six o'clock tonight."
