Removes the hard-coded timezone from constructor

I'm not sure what happened, but it appears you closed PR #7 without merging it in. Was that your intention?

I'm sending this pull request again, which fixes #6 and does the same thing #7 did. If you intended to close the PR without merging this in, then feel free to close this one without merging, as well, and I apologize for the duplicate PR, in that case. :-)

Thanks!