improve date query parsing (#1992)

[buschco]

What does this PR do?

Creating a new dayjs date, shows an offset of 2 hours whats makes sense rn since i live in Europe/Berlin Summer Time:
GMT+0200However, creating the date withdayjs(dateString.substr(11, 14), "Hmm");` will not work as expected (codesandbox playground):

dayjs("0200", "Hmm", "GMT").hour() 2
dayjs("0200", "Hmm", "Europe/Amsterdam").hour() 3

Correct me If i am wrong, but using dayjs to parse this string could be the issue here, so I wrote it w/o dayjs.

Could fix #1992 and #2250

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How should this be tested?

• Created an event in my apple calendar that should only allow one free slot. It showed the wrong time w/o the fix

Checklist

• I haven't added tests that prove my fix is effective or that my feature works

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployments, click below or on the icon next to each commit.

docs – ./apps/docs

🔍 Inspect: https://vercel.com/cal/docs/FYKGVivqcXYqrspbTmDM6JYKRay9
✅ Preview: Canceled

[Deployment for 33b0da1 canceled]

calendso – ./apps/web

🔍 Inspect: https://vercel.com/cal/calendso/AmKhqb1Ac4Zc3MFJjZEzsKv7Hjsr
✅ Preview: https://calendso-git-fork-buschco-fix-1992-cal.vercel.app

[Deployment for 33b0da1 failed]

[vercel]

@buschco is attempting to deploy a commit to the cal Team on Vercel.

A member of the Team first needs to authorize it.

[PeerRich]

thank you! we will take a look and test (@emrysal @zomars @alannnc)

[zomars]

Minor nitpick but it seems the the substr method is deprecated:

[buschco]

yeah you are right. I didn't want to change to much of the code, since substring is not a 1:1 replacement for substr
👍