egDate unit test fails on time change boundary

Evergreen 2.12.

'grunt test' reports:

  egDate
    ✗ should parse a simple interval
        Expected 169200 to be 172800.

The failing test is:

expect(egDate.intervalToSeconds('2 days')).toBe(172800);

==

When crossing time-change boundaries, "2 days" will not be equal to 48-hours worth of seconds. Patch coming that accepts 47, 48, and 49 hours worth of seconds as valid values.