Added support for shifting time forward/backward.

[cloudsydaniel]

Workflow now allows to shift time forward and backward by passing a pattern as an argument.

Pattern: +|-VALUE[mhdwMy] (minutes, hours, days, weeks, months, years)

Ie. df +30d will shift current time + 30 days; df -4w will subtract 4 weeks from current time.

[cloudsydaniel]

Forgot to mention that the new workflow has been zipped up and tested as well.

[kevinastone]

+1