My mistake, coding before thinking. Try this:
SELECT *
FROM Calendar c
CROSS JOIN employee e
LEFT JOIN attendlog a
ON a.eid = e.eid
AND a.CheckTIme = c.Date
WHERE c.[Date] >= CAST('20130801' AS DATETIME)
AND c.[Date] <= CAST('20130815' AS DATETIME)
ORDER BY e.eid
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden