Windows devices with Uptime more than 30 days

[PavlinS]

Hello, everyone!

Sorry for the noob question, but I have to create a report for all Windows devices with Uptime more than 30 days. I have managed to do the report and filter it to Windows only AssetType, however I can not figure out how to filter the Uptime criteria to show only devices with Uptime more than 30 days. 
Perhaps the criteria for tblAssets.Uptime or UptimeSinceLastReboot should be modified?

Thank you in advance!

Cheers!

Select Top 1000000 tblAssets.AssetID,
tblAssets.AssetName,
tblAssets.Domain,
tsysAssetTypes.AssetTypename As AssetType,
tblAssets.Username,
tblAssets.Userdomain,
tsysAssetTypes.AssetTypeIcon10 As icon,
tblAssets.IPAddress,
tsysIPLocations.IPLocation,
tblAssetCustom.Manufacturer,
tblAssetCustom.Model,
Coalesce(tsysOS.OSname, tblLinuxSystem.OSRelease, tblMacOSInfo.SystemVersion)
As OS,
tblAssets.SP,
tblAssets.Lastseen,
tblAssets.Lasttried,
Convert(nvarchar(10),Ceiling(Floor(Convert(integer,tblAssets.Uptime) / 3600 /
24))) + ' days ' +
Convert(nvarchar(10),Ceiling(Floor(Convert(integer,tblAssets.Uptime) / 3600 %
24))) + ' hours ' +
Convert(nvarchar(10),Ceiling(Floor(Convert(integer,tblAssets.Uptime) % 3600 /
60))) + ' minutes' As UptimeSinceLastReboot
From tblAssets
Left Join tsysOS On tsysOS.OScode = tblAssets.OScode
Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
Inner Join tsysAssetTypes On tsysAssetTypes.AssetType = tblAssets.Assettype
Inner Join tsysIPLocations On tsysIPLocations.LocationID =
tblAssets.LocationID
Inner Join tblState On tblState.State = tblAssetCustom.State
Left Join tblLinuxSystem On tblAssets.AssetID = tblLinuxSystem.AssetID
Left Join tblMacOSInfo On tblAssets.AssetID = tblMacOSInfo.AssetID
Where tsysAssetTypes.AssetTypename = 'Windows' And tblState.Statename = 'Active'
And tblAssets.Uptime Is Not Null
Order By tblAssets.Uptime Desc,
tblAssets.IPNumeric,
tblAssets.Domain,
tblAssets.AssetName