No way was there a single day in Vietnam that 1700 were killed. It would be 'interesting' to find out what day was the very worst, I'd guess a couple hundred possibly more. I dont know the casualties for Tet but they were probably higher. I think on 'average' 25 were killed per day but I'm not sure what time frame its counting, it might just be from a certain date instead of the whole 12 year involvement.
Ive got an old newspaper with an article entitled "217 GIs killed in week" from May 21st, 1970 on the front page but more than halfway down.
That site is interesting
http://www.mrfa.org/vnstats.htm
but his math is wrong on something i skimmed over
"170,000 Hispanics served in Vietnam; 3,070 (5.2%) of whom died there."
3,070 would be about 3% of 100,000. The percentage calculated is too high if the 170,000 is correct
Also his average age being 19 is incorrect
Edit:
oh ok the site says it was 155 on 17 Nov 65 from the 7th Cav, I think thats from the movie "we were soldiers." Didnt know they lost that much. I would think casualties from Tet would have exceeded that