hello,
i think the solution as suggested in this forum elsewhere implies that you have to follow it this way.
Assuming, you want to create 1hr time limit for a user in user-manager.
Note the following: In credit, create 1hr as the name, time put 2d, since you want the 1hr to last or expire after 2days, then you add your amount.
After that, for yo to create a user or add batch, your attention should be centred only on the uptime limit. This place it is 0s by default, but after you have selected you credit for the user, just put in the uptime limit =1h.
This will all the user to use the card for 1hr in 2days time. If he logs out he can reuse the card again.
Another important thing is to enable ntp client in the router, so that yo local time will be synchronized with any ntp server time yo choose.
open winbox, click on system--->Ntp Client, check enable, mode=unicast, then put the ip of the ntp server (primary and seconday) if you have only one, then put it there and click apply.
After that, go to system clock and set the time zone of you side. Please choose manual time set.
incase of ntp servers, try this link
http://www.pool.ntp.org/en/
Then choose yo region, africa, asia