add prevDay variable for previous day, primarily for queries

app/app.py

@@ -3,7 +3,7 @@ from flask import Flask, render_template, redirect, url_for, request, flash
 from flask_migrate import Migrate
 from werkzeug.security import generate_password_hash, check_password_hash
 from flask_login import (LoginManager, login_user, login_required, logout_user, current_user)
-from misc import datetime, date, time, currDay, ZoneInfo, currVersion, currCommit
+from misc import datetime, date, time, currDay, prevDay, ZoneInfo, currVersion, currCommit
 from db import (db, Period, Task, Event, User)
 from forms import (TaskForm, EventForm, PeriodForm, SignupForm, LoginForm, SettingsForm)
 from create_events import createEvents