In new step 2 will you be detecting both 'unixepoch' and ' unixepoch' (space character before the word) ? If you're allowing both in a liberal manner, can you allow 'epoch' and ' epoch' too ? But keeping compatibility by allowing just 'unixepoch' is okay too. What happens the value doesn't qualify for any of new steps 1 to 4 ? I suppose that would be either NULL or BLOB but perhaps there are other things. Perhaps the value is TEXT but the first character is not digit, plus, minus, or decimal separator.