The only efficient way to do what you want is to use a piece of JSL. Doing it using multiple formula columns would force the reading through a half a million records multiple times. The JSL below reads through the main table only once.
Also, you could do this all in one table, but then you would have to pretend you are using Excel and move all of the data from the lookup data table into the main table and then hid the columns. It wouldn't be pretty. Here is the script that I think should get you a long way into solving your issue. With a half a million records it takes a few minutes to do all of the required comparisons. Please note, the script is looking for 2 data tables with specific names.
Names Default To Here( 1 );
dtMain = Data Table( "Timestamp-1min" );
dtLookUP = Data Table( "Start-End-TS1" );
// Add the required new colummns
dtMain << New Column( "S Start-S End", format("h:m:s"));
dtMain << New Column( "T Start-T End", format("h:m:s"));
dtMain << New Column( "Day Length", format("h:m:s"));
dtMain << New Column( "Mid T", format("h:m:s"));
dtMain << New Column( "Twilight time", format("h:m:s"));
dtMain << New Column( "DT/TT", character);
// Loop through Main table and set values
DT = "";
dl = twTime = .;
For( i = 1, i <= N Rows( dtMain ), i++,
If( i == 1 | Day( dtMain:Timestamp[i] ) != Day( dtMain:Timestamp[i - 1] ),
theRow = Try(
(dtLookUp << get rows where(
dtLookUp:Month 2 == Month( dtMain:Timestamp[i] ) & dtLookUp:Date == Day( dtMain:Timestamp[i] )
))[1],
.
)
);
// Get the time for the current row
theTime = Date MDY( 12, 31, 1899 ) + 3600 * Hour( dtMain:Timestamp[i] ) + 60 * Minute( dtMain:Timestamp[i] )
+Second( dtMain:Timestamp[i] );
theNextTime = Date MDY( 12, 31, 1899 ) + 3600 * Hour( dtMain:Timestamp[i + 1] ) + 60 *
Minute( dtMain:Timestamp[i + 1] ) + Second( dtMain:Timestamp[i + 1] );
// If this is a Twilight Start, record the time, and set the value for Twilight time
If( dtLookUp:Twilight start[theRow] >= theTime & dtLookUp:TwilightStart[theRow] <= theNextTime,
dtMain:"T Start-T End"n[i] = dtLookUp:Twilight start[theRow];
DT = "TT";
twTime = dtLookUp:Twilight Length[theRow];
);
// If this is Sunrise, recorde the time and set the value for Day Length
If( dtLookUp:Sunrise[theRow] >= theTime & dtLookUp:Sunrise[theRow] <= theNextTime,
dtMain:"S Start-S End"n[i] = dtLookUp:Sunrise[theRow];
DT = "DT";
dl = dtLookUp:Day Length[theRow];
);
// If sunset has ended record the value and blank out the day length time
If( dtLookUp:Sunset[theRow] >= theTime & dtLookUp:Sunset[theRow] <= theNextTime,
dtMain:"S Start-S End"n[i] = dtLookUp:Sunset[theRow];
DT = "TT";
dl = .;
);
// If twighlight has ended record the value and blank out the Twilight time
If( dtLookUp:Twilight End[theRow] >= theTime & dtLookUp:Twilight End[theRow] <= theNextTime,
dtMain:"T Start-T End"n[i] = dtLookUp:Twilight End[theRow];
DT = "";
twTime = .;
);
// If this is the Mid T time, record the value
If( dtLookUp:Mid T[theRow] >= theTime & dtLookUp:Mid T[theRow] <= theNextTime,
dtMain:Mid T[i] = dtLookUp:Mid T[theRow]
);
// Write the repeating values
dtMain:"DT/TT"n[i] = DT;
dtMain:Twilight time[i] = twTime;
dtMain:Day Length[i] = dl;
// Do some cleanup on ending records
If( Is Missing( dtMain:"S Start-S End"n[i] ) == 0 & Is Missing( dtMain:Day Length[i - 1] ) == 0,
dtMain:Day Length[i] = dtMain:Day Length[i - 1]
);
If( Is Missing( dtMain:"T Start-T End"n[i] ) == 0 & Is Missing( dtMain:Twilight time[i - 1] ) == 0,
dtMain:Twilight time[i] = dtMain:Twilight time[i - 1]
);
If( Is Missing( dtMain:Twilight time[i] ) == 0 & dtMain:"DT/TT"n[i] == "",
dtMain:"DT/TT"n[i] = dtMain:"DT/TT"n[i - 1]
);
);
Jim