finding index of precise value

Hi all, I try to use this function:

l=find(find(strcmp(Time,'09:00:00'))). Time is an known cell.

How could make a loop for this function to find the index of each minute:

l=find(find(strcmp(Time,'09:00:00')))
l=find(find(strcmp(Time,'09:01:00')))
l=find(find(strcmp(Time,'09:02:00')))
.
.
.
l=find(find(strcmp(Time,'10:00:00')))
l=find(find(strcmp(Time,'10:01:00')))
and so on

Thie Time cell is of 500ms steps.

Thank you

Answer 1

[Andrei Bobrov]

d = datenum(Time);
vt = datevec(d);
out = find(vt(:,6) == 0);