What is the formula for converting 1min data to higher time frames?

If I have a bunch of 1 minute data, what is the formula to convert it to higher time frames?

 

To convert 1 minute bars to n minute bars:

Start with a bar with time stamp xx Hour 01 Min.

Highest high of 01 to n minutes is your n minute high.

Lowest low of 01 to n minutes is your n minute low.

Bar close is the n minute bar close.

Repeat starting at xx Hour (n + 01) Min and so on until you run out of data..

 

y - (z % y) + z

where:

- y is your higher interval number (3min, 5min etc)
- z is your 1 min bar time

output will give you your higher interval bar time.

then just do the high/low comparisons as jeb mentioned on each 1min update.