You have 90 days from the date your passport was issued to report that you have not yet received it in the mail. If you do not report the non-receipt of your passport within 90 days of the issue date, you will be required to reapply and submit the full passport fee.
The best time of year to see the Northern Lights in Iceland is between the months of September and March. To be in with a really strong chance to witness the northern lights a cloudless, clear sky is the main requirement with the outside temperature being cold but dry.
In Sweden, the northern lights usually occur during the winter months through late March or early April, but they can be spotted as early as September in the northernmost parts. Your best chance of catching a glimpse of the northern lights is on cold winter nights when the sky is clear, dark with little to no moonlight, and cloudless.