Question: When I tried to draw circle on JMapViewer with the following parameters:

Latitude:30.58654740901267
Longitude:31.504483034999993
radius : 100

I got the following gigantic circle
![enter image description here](https://i.stack.imgur.com/7Y3Ig.png)

**What is the measurement unit used for this radius variable ?!!**

**code below**

```
MapMarkerCircle circle = new MapMarkerCircle(c, 100);
Color color = new Color(50, 0, 0,100);
circle.setBackColor(color);
mapViewer.addMapMarker(circle);

```

Answer: 
The `COleDateTime` [(link)](http://msdn.microsoft.com/en-us/library/38wh24td.aspx) and `COleDateTimeSpan` [(link)](http://msdn.microsoft.com/en-us/library/xb7yw6f3.aspx) classes could be used.

```
#include <atlcomtime.h>

COleDateTime dt = COleDateTime::GetCurrentTime();
COleDateTimeSpan span(90, 0, 0, 0);
COleDateTime dt2 = dt - span;

```
Not a single function, no.

But you can quite easily do this:

* Obtain current time using [`time()`](http://linux.die.net/man/2/time).
* Subtract 90 days' worth of seconds.
* Convert to local time using [`localtime()`](http://linux.die.net/man/3/ctime).
* Convert to string using [`strftime()`](http://linux.die.net/man/3/strftime) if needed.