write_swmm_dat: Write xts-objects to .dat file format
In dleutnant/tsconvert: Read and Convert Time Series Data

Writes a xts-object to .dat structured time series data format usually interpreted by the stormwater management model 'SWMM'.

1 2	write_swmm_dat(xts, file, is_rainfall = FALSE, seconds = -60, is_caldata = FALSE, digits = 6)

`xts`	The xts object to be written.
`file`	A character string naming the file to write to.
`is_rainfall`	logical. TRUE shifts coredata values with specified seconds (default is -60)
`seconds`	The seconds to shift to.
`is_caldata`	logical. Modifies the header if .dat output.
`digits`	Number of digits to write.