Learn English – Which is the correct preposition: at or from

"Working from home" seems to be the standard current idiom for telecommuting. The connotation seems to be that your work is still centered around the workplace, but you are completing it remotely. Under this theory, "working at home" would still be preferred in cases where you were self-employed (so your workplace is your home) or where the work was actually centered at home for some reason (for instance if your job was assembling something and you took it home and assembled it there instead).

In that sense, you can use 'by' with any tense. Consider its meaning as given by the Longman dictionary:

Before or not later than a particular time.

Examples:

• The document needs to be ready by next Friday.
• By the end of the day we had sold over 2000 tickets.
• By the time we got home we were tired and hungry.
• I'll be home by 9:30.
• Please try to have this done by Friday.

All the examples are borrowed from the Longman dict. so you can trust them.