this will convert the passed date into the equivalent time in the given timezone. If no 'from' timezone is given the local timezone is used. Similarly for the 'to' timezone. If no time or date is given then the current time is used. Only one of the time or date can be given. A time or date must be given if the 'from' timezone is given.
This uses the param package and so it has access to the help parameters
which give a comprehensive message describing the usage of the program and
the parameters you can give. The -help parameter on its own will print the
standard parameters that the program can accept but you can also give
parameters to show both more or less help, in more or less detail. Other
standard parameters allow you to explore where parameters have been set and
where they can be set. The description of the -help parameter is a good
place to start to explore the help available.
The intention of the param package is to provide complete documentation
for the program from the command line.
This offers version-querying parameters that allow the user to discover the program version.