This tag implies that the bands and artists are Serbian or originated in Serbia. Music represented by this tag is often highly commercial. Other, possibly better, Serbian tags are, for example Novi Val or nova srpska scena.
Relapse means that the teeth can take up to one year or more to stabilize after treatment. If you had gaps between your teeth before treatment, the retention period will be longer. Usually, retainers are worn for as long a time as you have had your braces.
Late to the party but here's my answer: Depends how much they moved your teeth during braces - usually 10 days is fine but don't forget the lab needs some time to churn out a new retainer. Once you get back, see if your dentist can make you a new Essix (plastic) retainer out of a mold of your teeth.