IDEA doesn't say 60 "school day" or 60 "business days," it says 60 days.
From thr horse's mouth @
https://web.archive.org/web/2008051...0/edocket.access.gpo.gov/2006/pdf/06-6656.pdf:
Procedures for Initial Evaluation
(§ 300.301(c))
Comment: Numerous commenters
requested that the regulations clarify
when the 60-day timeframe for a public
agency to conduct an initial evaluation
begins. One commenter requested that
the 60-day timeframe include
completing both the evaluation and
eligibility determination.
Several commenters recommended
reducing the timeframe for evaluations
from 60 days to 30 days. Some
commenters recommended that the 60-
day timeframe be 60 school days. A few
commenters stated that the timeframe
for evaluation should be longer if
additional time is required for specific
assessments, such as behavioral
assessments or other assessments based
on scientific practices.
Discussion: It would be inconsistent
with the Act to reduce the timeframe
from 60 days to 30 days, require the 60-
day timeframe to be 60 school days,
extend the timeframe for particular
types of assessments, or require that the
60-day timeframe cover both the
evaluation and determination of
eligibility. Section 614(a)(1)(C)(i)(I) of
the Act requires an initial evaluation to
be conducted within 60 days of
receiving parental consent for the
evaluation or, if the State establishes a
timeframe within which the evaluation
must be conducted, within that
timeframe. The regulations in
§ 300.301(c) reflect this requirement.
Changes: None.
Also,
Discussion: Section 300.301(c),
consistent with section 614(a)(1)(C)(i)(I)
of the Act, requires an initial evaluation
to be completed within 60 days of
receiving parental consent for
evaluation or, if the State establishes a
timeframe within which the evaluation
must be conducted, within such
timeframe. The Department declines to
require that a State-established
timeframe be less than 60 days or to
place additional requirements on States
with timeframes of greater than 60 days
because the Act gives States the
authority to establish different
timeframes and imposes no restrictions
on State exercise of that authority. We
believe this is evidence of an intent to
permit States to make reasoned
determinations of the appropriate
period of time in which evaluations
should be conducted based on
particular State circumstances.
Changes: None.
There's more on this issue at the url provided. Due a search on "60-day."
Every State has law that parallels the Federal IDEA 2004. Check your State law. State law MUST adhere to the Federal regs except in areas where the Federal law is silent. Even with-that, it's my understanding the States may not circumvent or violate the spirit of the Federal law.