Range Calculation from Custom High To Low

Before we can even approach a solution we need to explain how bars on the chart are marked with date/time data in Thinkorswim. The time assigned to each bar is the start time. So if you have a user input value of 930 it will pick up the candled that started trading at 9:30. So if that candled is on a 15 min chart, that candle closes at 9:44:59.

The next item we need to tackle is how the value in the label will change as new bars are added to the chart. Before 9:30 the label will display the range from the previous day. After 9:30 and before 14:30 today, the label will display the range from yesterday's low at 14:30 to today's high at 9:30. Only after the 14:30 bar from today has completed with the label switch to display the range from today's 9:30 high to today's 14:30 low. Is this the behavior you expected? If not, the solution is far more complex than you can imagine.

Edit: After getting clarification on this request in the comment section below I have a solution:

input timeOfHigh = 930;
input timeOfLow = 1430;
rec targetHigh = if SecondsTillTime(timeOfHigh) == 0 then high else targetHigh[1];
rec targetLow = if SecondsTillTime(timeOfLow) == 0 then low else targetLow[1];
AddLabel(yes, Concat("Range: ", targetHigh - targetLow), Color.WHITE);