datetime::to_string causes crash when m_interval is zero

[bandrews-spirent]

Previously, if datetime was zero, to_string would return "1601-01-01T00:00:00Z"
After upgrading to 2.10.14, sprintf_s throws with "Buffer too small, 0".

[bandrews-spirent]

I worked around it by adding

if (m_interval <= 0)
{
    return U("1601-01-01T00:00:00Z");
}

just before this line
const int64_t epochAdjusted = static_cast<int64_t>(m_interval) - NtTo1900OffsetInterval;

[surendernitj]

We are also hitting this issue while using C++ Azure storage sdk and work around for us is expensive/breaking change

Azure/azure-storage-cpp#379

Any help would be appreciated.