List the weeks between now and a given date

list_weeks.sh

#!/bin/bash

# Lists the weeks between now and $1.	You may specify the end date in any
# way that GNU date accepts, such as "Aug 25", "next year" or "2 months".
#
# If your system date is BSD date (like on Mac OS X), you will need to install
# GNU coreutils, ideally with http://mxcl.github.com/homebrew/
# "brew install coreutils"

FORMAT="Week of %b %e, %Y: "
DAY_TO_PRINT="Monday"
DATE_CMD="gdate" # Use gdate if your system date is BSD date (Mac OS X)
# DATE_CMD="date" # Use this if your system date is GNU date (Linux)

END_T="`$DATE_CMD -d "$1" +%s`"
NEXT_WEEK=0

NEXT="$DAY_TO_PRINT +$NEXT_WEEK week"
NEXT_T="`$DATE_CMD -d "$NEXT" +%s`"
while [ "$NEXT_T" -lt "$END_T" ]; do
	gdate -d "$NEXT" +"$FORMAT"
	NEXT_WEEK="$(($NEXT_WEEK + 1))"
	NEXT="$DAY_TO_PRINT +$NEXT_WEEK week"
	NEXT_T="`$DATE_CMD -d "$NEXT" +%s`"
done