[600MRG] WSPRX resync question

[Pat Hamel]

The past week or so I have had a good trace on the waterfall but no decodes.
 I resync the computer to time.windows.com every night after I turn off my
QRSS3 beacon to let WSPRX run all night unless storms are predicted.
 Last night in an hour I finally got only one capture, and it said the DT
(time delta) was 2.3 seconds.
For some reason time.nist.com is not available here, is time.windows.com
actually off by 2.3 seconds ?
Thank you,
Pat W5THT & WD2XSH/6