here is what i use for 30 days. you could change the 30 to something like 15 for 15 days.
Select Top 1000000 tblAssets.AssetID,
tblAssets.AssetUnique,
tblAssets.Domain,
tsysOS.OSname,
tblAssets.Lastseen As [Last Seen],
tsysOS.Image As icon,
tblAssetCustom.Manufacturer,
tblAssetCustom.Model,
TsysChassisTypes.ChassisName As Type,
tblAssets.Username
From tblAssets
Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
Inner Join tsysOS On tblAssets.OScode = tsysOS.OScode
Inner Join tblSystemEnclosure
On tblAssets.AssetID = tblSystemEnclosure.AssetID
Inner Join TsysChassisTypes On tblSystemEnclosure.ChassisTypes =
TsysChassisTypes.Chassistype
Where tblAssets.Lastseen < GetDate() - 30 And tblAssetCustom.State = 1
Order By [Last Seen] Desc,
tblAssets.AssetName