```
def findMinDifference(self, timePoints):
t = [0] * 24 * 60 #array for the time. they are buckets
for s in timePoints:
v = int(s[:2]) * 60 + int(s[3:5])
if t[v]==1: return 0 #find duplicate time
t[v] = 1
tt = t + t # concat two time arrays together, to handle cases like [23:59, 00:01]
ans = 24*60 # value to return
prev = -24*60
for i in xrange(len(tt)):
if tt[i]:
ans = min(ans, i-prev)
prev = i
return ans
```