timestamp & graph time scale

Hi All,
This is my very basic question.
I have follwing table in database.
result_time | epoch | nodeid | light |
parent | voltage
----------------------------+-------+--------+-------+--------+---------
2004-12-09 16:44:43.501375 | 1 | | |
|
2004-12-09 16:44:43.564375 | 2 | 10 | 362 |
0 | 479
2004-12-09 16:44:43.626375 | 3 | 10 | 408 |
0 | 478
2004-12-09 16:44:43.689375 | 4 | 10 | 429 |
0 | 478
2004-12-09 16:44:43.751375 | 5 | 10 | 438 |

I need to plot the light Vs Time.
For plotiing the data I am using G2Dint java API. To
plot time on x axis I need to convert time to some
integer value (suppose I choose x-axis scale in
minute)
How can I convert Timestamp time to an integer minute.
As my database is having data over months of period,
actually I need to plot values Vs time. Is there any
Idea so that I can plot light Vs time ( and can show
date along with time). IFAIK G2Dint takes float or
integer values to plot them along x axis and y axis.
How can I show the time on X axis (with date).
Thanks for help.
Regards:
santosh dwivedi

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