#date date
Specifies the observation date of the following data in the data file. Note that this does not apply if the date is explicitly defined using the #data command.
A variety of date formats are acceptable to snap, examples being:
The default observation date is "unknown" if it is not specified in the data file.
The observation date is used to calculate the effect of deformation on observations. Observations without a specific date (ie the date is "unknown") cannot be used in adjustments that include a deformation model. Observation dates may be used to reweight, reject, or ignoring observations and for recoding stations used in the observation.