SCALABLE ZOOM CALENDARS

1 . A computer-implemented method for adjusting a start date and an end date of a displayed timeline in a calendar application on a touch screen device comprising:

identifying, using a processing device, a touched first point and second point within the calendar application displaying the timeline across a first dimension on the touch screen device;

responsive to a dragging of at least one of the touched points, calculating a change in a distance between the first point and the second point;

identifying whether the dragging corresponds to a zooming in or a zooming out based on the calculated distance change;

scaling the calculated change in distance with a scaling factor that varies for different units of time in the calendar application;

dividing the scaled calculated change in distance by the width of the displayed timeline and by an adjustment factor to calculate a date change amount; and

adjusting the start date and the end date of the displayed timeline by the calculated date change amount according to whether the dragging is identified as corresponding to the zooming in or the zooming out.

2 . The computer-implemented method of claim 1 , further comprising:

changing a timescale shown in the timeline displayed across the first dimension based on the adjusting of the start date and the end date.

3 . The computer-implemented method of claim 2 , further comprising:

identifying a direction of the dragging;

when the identified direction is vertical, changing a width of at least one calendar entry displayed in the timeline; and

when the identified direction is horizontal, adjusting the start date and the end date of the displayed timeline and changing the timescale shown in the timeline.

4 . The computer-implemented method of claim 1 , wherein the dragging is identified as the zooming in when the calculated distance change between the touched points increases and the dragging is identified as the zooming out when the calculated distance change between the touched points decreases.

5 . The computer-implemented method of claim 1 , wherein the dragging is identified as the zooming in when the calculated distance change between the touched points decreases and the dragging is identified as the zooming out when the calculated distance change between the touched points increases.

6 . The computer-implemented method of claim 1 , further comprising:

identifying a midpoint date displayed in the timeline that is associated with the touched points; and

zooming the timeline around the identified midpoint date when zooming into or out of the timeline.

7 . The computer-implemented method of claim 1 , further comprising:

caching calculated changes to the distance between the first point and the second point as the user drags at least one of the points; and

zooming into or out of the timeline only after the cached calculated change to the distance exceeds a threshold value.

8 . The computer-implemented method of claim 1 , further comprising:

responsive to the zooming into the timeline, displaying additional information associated with each calendar entry on the screen within the adjusted start date and the adjusted end date of the timeline; and

responsive to the zooming out of the timeline, consolidating calendar entry information displayed on screen to display less information on the screen.

9 . The computer-implemented method of claim 1 , wherein the displayed additional information includes at least one of a sub-activity completion status bar, statistical information of a respective calendar entry between the adjusted start date and the adjusted end date, and a sub-activity progress bar.

10 . The computer-implemented method of claim 2 , wherein the timescale is a multidimensional timescale including a primary timescale and a secondary timescale having a unit of time that is a subset of the primary timescale.

11 . The computer-implemented method of claim 10 , wherein the changing of the timescale shown in the timeline includes changing at least one of the primary timescale and the secondary timescale.

12 . The computer-implemented method of claim 11 , wherein the primary timescale is selected from the group consisting of years, half-years, quarters, months, weeks, days, and the secondary timescale is a subset of the primary timescale.

13 . The computer-implemented method of claim 12 , wherein the primary timescale is quarters and the secondary timescale is months and responsive to the zooming out of the calendar application, the primary timescale changes from quarters to years and the secondary timescale changes from months to quarters.

14 . The computer-implemented method of claim 12 , wherein the secondary timescale continues to show months though the space allocated for each month on the screen is reduced.

15 . The computer-implemented method of claim 1 , further comprising, responsive to the first point and the second point being contained within a single calendar entry on the display, performing at least one of:

displaying additional information including sub-activities associated with the single calendar entry on the screen corresponding to a zoomed in time period when zooming into the single calendar entry; and

consolidating calendar entry information displayed on the screen to display less information on the screen about the single calendar entry when zooming out of the single calendar entry.

16 . The computer-implemented method of claim 1 , wherein one of a finger or an electronic device is used to touch the first point and the second point on the screen and drag the at least one point.

17 . A non-transitory computer readable medium comprising stored instructions that when executed by a processing device, cause the processing device to:

identify a touched first point and second point within a calendar application displaying a timeline across a first dimension on a touch screen device;

responsive to a dragging of at least one of the touched points, calculate a change in a distance between the first point and the second point;

identify whether the dragging corresponds to a zooming in or a zooming out based on the calculated distance change;

scale the calculated change in distance with a scaling factor that varies for different units of time in the calendar application;

divide the scaled calculated change in distance by the width of the displayed timeline and by an adjustment factor to calculate a date change amount; and

adjust a start date and an end date of the displayed timeline by the calculated date change amount according to whether the dragging is identified as corresponding to the zooming in or the zooming out.

18 . The non-transitory computer readable medium of claim 17 , wherein the execution of the stored instructions further cause the processing device to change a timescale shown in the timeline displayed across the first dimension based on the adjusting of the start date and the end date.

19 . A system comprising:

a touch sensitive screen;

a position calculation module for identifying a touched first point and second point within a calendar application displaying a timeline across a first dimension on a touch screen device, responsive to a dragging of at least one of the touched points, calculating a change in a distance between the first point and the second point, scaling the calculated change in distance with a scaling factor that varies for different units of time in the calendar application, and dividing the scaled calculated change in distance by the width of the displayed timeline and by an adjustment factor to calculate a date change amount; and

a zoom module for identifying whether the dragging corresponds to a zooming in or a zooming out based on the calculated distance change and adjusting a start date and an end date of the displayed timeline by the calculated date change amount according to whether the dragging is identified as corresponding to the zooming in or the zooming out; and

a timescale module for changing a timescale shown in the timeline displayed across the first dimension based on the adjusting of the start date and the end date.

20 . The system of claim 19 , further comprising a cache storing calculated changes to the distance between the first point and the second point during the dragging, wherein the zoom module adjusts the start date and the end date of the calendar application only after a stored calculated change in the cache exceeds a threshold value.