Why is the sentence " There is (62) days left until we have to take the exam." correct? [duplicate]

The grammatically sound sentence should be:

There are 62 days left.

However, the simplified version There is (most commonly, if not exclusively in its contracted form There's) seems to be gaining increasing popularity, possibly under the influence of non-native speakers of English.

Francophones, too, have no plural construction for this: "il y a" means both there is and there are.

Part of this trend among Anglophones seems to be corresponding with the theory that languages become more simplified over time, as people break the established patterns.

Also, part of the confusion could be because when distances, periods of time, sums of money, etc. are used as subjects, they're considered as units and hence get singular verbs:

Ten miles is too far to walk.

100 dollars is too much to pay.

Five years is too long for that offense.