You might have wandered that Slide to Unlock text can be replaced with something more useful or use of default Clock space for Jailbreak Tweaks like IntelliScreenX to display addition information then Greensnow has released a useful tweak which allows you to display Clock on Slide to Unlock Bar. As there are lots of tweaks available for lockscreen which allow you to change the content that are being displayed on LockScreen therefore this tweak does not conflict with them. All you need to do is hide the default clock screen from IntelliScreenX and time be kept on Slide to Unlock bar which also displays seconds.
Install the tweak from Cydia for free and when the tweak is installed you can simply view the time on LockScreen and use the upper half for displaying other notifications. The only drawback of the tweak is that it hides the slider but the functionality remains the same.
Note:- In order to unlock your device, you need to slide all the way starting from one end to another.