If I want to say, please send me the forecast until July next year. Can I replace "until" with "through" or "as of"? Thanks in advance.
Until: Continue this action up to the specified point, then stop. So, "please send me the forecast until July next year" will get you the forecasts up to June 30th next year, then they will stop.
Through: Continue this action up to the END of the specified point, then stop. "Please send me the forecast through July next year" will get you the forecasts up to July 31st next year, then they will stop.
As of: Begin this action at the specified point. "Please send me the forecast as of July next year" would probably get you a confused message, since it is normally used to refer to past data. For example, "What are our total sales as of March 15th?" would refer to sales data up to the point of March 15th of the current year, even if more data is available.
There are some alternatives to until in this context; "Up to" would be the closest. However, until is probably the correct word to use.
I would use "through", in the sense of definition 4 c in Merriam-Webster.
Please send me the forecast through July of next year.
If you use "until July" it sounds like you are asking the person to start sending the forecast now and to send it continuously, only stopping in July.
If you use "as of July" it sounds like you want a forecast that will be made in July, which doesn't really make sense.