Re: Question about DayOfWeek

*To*: mathgroup at smc.vnet.net*Subject*: [mg126210] Re: Question about DayOfWeek*From*: István Zachar <replicatorzed at gmail.com>*Date*: Wed, 25 Apr 2012 00:34:51 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jn5s97$nvl$1@smc.vnet.net>

If I understand it correctly, the "Calendar`" package uses symbols for days instead of strings. Thus what is returned by Needs["Calendar`"]; DayOfWeek[{1975,1,1}]==Thursday is a symbol-to-symbol comparison (Wednesday==Thursday), just like a==b, and since none of the symbols have any value, Equal (==) is left unevaluated. Use SameQ insted of Equal: In[6]:= DayOfWeek[{1975, 1, 1}] === Wednesday Out[6]= True In[7]:= DayOfWeek[{1975, 1, 1}] === Thursday Out[7]= False Hope this helps, Istvan On Tuesday, April 24, 2012 10:37:43 AM UTC+1, Kent Holing wrote: > DayOfWeek[{1975,1,1}]==Wednesday gives True (as it should), but DayOfWeek[{1975,1,1}]==Thursday gives > Wednesday == Thursday and not False, as it should? Why is it so?