Centering Waveform at Zero for FFT

I want to perform a FFT on a waveform that describes a Gaussian pulse in amplitude vs. time. I also want to have that pulse centered so that its maximum is at t = 0.
So far I have been using Amplitude and Phase Spectrum.vi and FFT Spectrum (Mag-Phase).vi. The problem with the former is that it only takes a 1D array of Y values, not another array for time values. The problem with FFT Spectrum (Mag-Phase).vi is that I don't know how to use the t0 component (it requires a timestamp?).
I have tried "wrapping" the pulse around, i.e. cutting the first half of the pulse and concatenating it to the end but this doesn't have the FFT I want (which would have constant phase in frequency domain).
A bit about my background: I'm an undergrad volunteering in an ultrafast spectroscopy lab, so it's very possible I'm ignoring something very elementary here about FFT, which I still treat as something of a black box, so any help in that topic would be welcome.

Hello,
In the Amplitude and Phase Spectrum vi, the time values are accounted for by wiring the dt input of the function. This assumes that you have a constant dt between each point and the very first point is treated as t=0. The other function behaves similarly except that you are using a waveform. A waveform consists of 1) Amplitude values, 2) t0 (timestamp - for you, the timestamp can just be an arbitrary constant value) 3) dt (again, this make it a constant dt between all the points) 4) Attributes. Overall, you should get similar results from either of these. In terms of your data, do they have a constant time interval between points or not?
-Zach
Certified LabVIEW Developer

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