This link explain fully details about dates in asset accounting http://help.sap.com/saphelp_erp60_sp/helpdata/en/4f/71fd71448011d189f00000e81ddfac/frameset.htm
Therefore, I should not mention the same things here. It gives already description about default asset value date determined in SAP across modules. You can specify how system default asset value date in SPRO as this route: SPRO -> Financial Accounting -> Asset Accounting -> Transactions -> Specify How Default Asset Value Date is Determined.
And one more additional thing that I want is that Asset Value Date of one transaction should be in the same fiscal year with Posting Date. If not, It will not allow to post or system use other dates (Posting date). For i.e., if you use CJ88 with directly entered asset value date differ from current fiscal year( of posting date), you get an error. Meanwhile, using F-90 for asset acquisition, if document date is in current fiscal year, document date will be the asset value date. If document date is in previous fiscal year, posting date will be chosen. That is miracle behind the sceneJ.