Queries :: Selecting All Date Fields Between Two Dates?

I'm trying to select a range of relevant dates for an amortization calculation (see my earlier thread on this subject here), but I'm having a bit of trouble making the SQL work.

I have a table called "t_AllMonths" that has only one field: MonthStartDate which contains the first day of the month for a very wide range of months over something like a ten-year period. I'm calculating amort for assets which will be amortized for some subset of those months (defined by the asset's Amort Start Date and Amort End Date). Further complicating matters, the amortization may be suspended during certain "hiatus" periods when the asset it not planned to be in use, and may differ by which business units make use of the asset.

So, I have three tables.

Table: t_Assets
Fields: AssetID (autonumber; primary key), Asset_Name, Asset_Cost

Table: t_AllMonths
Fields: MonthStartDate

Table: t_AmortPeriods
Fields: AmortPeriodID, AssetID, Amt_Period_Num (which I don't expect to use in this), StartDate and EndDate

Right now, I'm just trying to pull the range of dates between the earliest amort start date and the latest amort end date. (Min of StartDate and Max of EndDate, respectively) for a given AssetID.

My sql looks like this:

SELECT t_AllMonths.MonthStartDate,
Min(t_AmortPeriods.StartDate) AS MinOfStartDate, Max(t_AmortPeriods.EndDate) AS MaxOfEndDate,
t_Assets.AssetID
FROM t_AllMonths,
t_Assets INNER JOIN t_AmortPeriods ON t_Assets.AssetID = t_AmortPeriods.AssetID
WHERE ((t_AllMonths.MonthStartDate) Between [MinOfStartDate] and [MaxOfEndDate]);

I keep getting an error message that reads "Run-Time Error 3122: You tried to execute a query that does not include the specified expression MonthStartDate as part of an aggregate function."