I have a cron job that gets results from the DB to check it the interval set by user falls on today's date. I am currently thinking of doing it as below :
Get the time column for the row. Ex:2017-05-25 00:00:00
Get the frequency set. Ex:Every 2 weeks.
Get the current date in above format. Ex:2017-05-31 00:00:00
Get the difference in days. Ex:6 days.
Convert the frequency set to days. Ex:2 weeks = 14 days;
Divide (difference in time(days)) by (frequency in days). Ex:6/14
This way I will only get the result to be true when 2 weeks have passed since the time set. I.e., 14/14, 28/14, 42/14,...
If the frequency is in months, I can start dividing by 30. But somehow this feels like a hacky way of doing it. So my question is if there is better way of doing this calculation to check the difference.
This is what I have done as explained by above example.
` $frequency = ; // Get the relevant fields from db
$today = date(Y-m-d H:i:s);
foreach ($frequency as $key => $value) {
$frequency_in_days;
$frequency_type = $value->type;
$frequency_repeat = $value->repeat;
if($frequency_type == 1){
$frequency_in_days = $frequency_repeat;
} elseif($frequency_type == 2) {
$frequency_in_days = $frequency_repeat * 7;
} elseif($frequency_type == 3) {
$frequency_in_days = $frequency_repeat * 30;
} elseif($frequency_type == 4) {
$frequency_in_days = $frequency_repeat * 365;
}
// Get number of days spent between start_date and today in days.
$interval = date_diff($value->start_date, $today)->format('%a');
$result = $interval % $frequency_in_days;
if ($result == 0) {
// Frequency falls today! Do the job.
}
}`
Note: The cron job runs this script. The script again needs to check if the today falls under the frequency set.
Also for argument's sake, is this the best logic to calculate the difference?
Thank you.
This will work
Table "schedule"
`last_run` timestamp,
`frequency_seconds` int
example query for tasks that should go every two weeks:
SELECT *
FROM schedule
WHERE TIMESTAMPDIFF(last_run, NOW()) >= frequency_seconds
after fetching rows update last_run to NOW()
Related
A time attendance system can have many shifts.
For instance:
Shift a) 08:00 - 16:00,
Shift b) 16:00 - 00:00,
Shift c) 00:00 - 08:00,
A user starts working at 07:55 what is the best way to match this user with the correct shift which is shift a?
Keep in mind that the time attendance system may have many shifts much closer together, for instance a
shift that starts at 8:00 and a shift that starts at 9:00.
Important info:
What i have done is a foreach loop that compares all starting times of the shifts (in our example 09:00, 16:00, 00:00) with the time that user started working. In our example 7:55.
The one that is closer to the users start working time is the correct shift.
This looks like its ok but in reality its not. The reason is that when time is round 00:00:00 and since times of shifts do not have a date, when the comparison is 23:59:59 and 00:00:01 i get 86400 secs instead of just 2 secs.
Additional you never know which date is greater than the other, because a user may come earlier for work or late.
So any ideas must take these into consideration.
Thanks for efforts
I've updated the answer based on the comment, but there is not enough information in the question to show you how to query your database and convert your shifts into the array I'm using in this example.
This codeblock is reference, not code to use. This is the array of start times you need to convert your database table to.
$shift_starts = [
// 1 represents the ID of the shift in your database.
1 => [
// Shift ID 1 starts at midnight, hour 0, minute 0
[0, 0],
],
// 2 represents the ID of the shift in your database.
2 => [
// Shift ID 2 starts at 8am, hour 8, minute 0
[8, 0],
],
// 3 represents the ID of the shift in your database.
3 => [
// Shift ID 3 starts at 4pm, hour 16, minute 0
[16, 0],
],
];
Create a function, something like this. Again, I don't know how you are querying your database, nor the schema. I just know how you are storing the start times:
// Psudeo Code!!! Study and write your own function that returns
// the array as defined above.
function get_shift_start_array() {
$shift_starts = [];
$result = mysqli_query($db, "SELECT * FROM shifts ORDER BY start_time");
while ($row = mysqli_fetch_row($result)) {
// If the start_time is formatted h:m:s, then make it so you can get hours
// and minutes into their own variables:
$arr = explode(':', $row['start_time']);
$hour = $arr[0];
$minute = $arr[1];
$shift_starts[$row->id] = [$hour, $minute];
}
return $shift_starts;
}
Now that we have a way to get your shift data into a format we can code around, this function will take a unix timestamp and return the database ID of the shift. (Notice this function calls the function above)
Read the comments and study the PHP functions you might not understand.
/**
* Get the shift ID for a specific time.
*
* #param int $punchin_time Unix timestamp Default is the current time.
* #return int The shift id (the array key from $shift_starts)
*/
function findShift($punchin_time = null): int
{
if ($punchin_time === null) {
$punchin_time = time();
}
// Call the psudo code function to get an array of shift start times keyed by shift id.
$shift_starts = get_shift_start_array();
// Set $day to the unix timestamp of midnight yesterday.
$day = strtotime(date('Y-m-d', $punchin_time - 86400));
// We'll be checking the difference between punchin time and the shift time.
// $last_diff will be used to compare the diff of the current shift to the last shift.
// Initialize this with an arbitrarily high value beyond the 3 days we're looking at.
$last_diff = 86400 * 5; //
$last_index = null;
// Loop over 3 days starting with yesterday to accommodate punchin times before midnight.
// Return the shift ID when we find the smallest difference between punchin time and shift start.
for ($i = 0; $i <= 3; $i++) {
// Get the month, day, and year numbers for the day we are iterating on.
// We will use these in our calls to mktime()
$m = date('n', $day);
$d = date('j', $day);
$y = date('y', $day);
// Loop over each shift.
foreach ($shift_starts as $index => $start) {
// Create a unix timestamp of the shift start time.
// This is the date and time the shift starts based on the day iteration.
$time = mktime($start[0], $start[1], 0, $m, $d, $y);
// Get the difference in seconds between this shift start time and the punchin time.
$diff = abs($punchin_time - $time);
// $diff should be getting smaller as we get closer to the actual shift.
if ($diff > $last_diff) {
// If $diff got bigger than the last one, we've past the shift.
// Return the index of the last shift.
return $last_index;
}
$last_index = $index;
$last_diff = $diff;
}
$day = strtotime('+1 day', $day);
}
// Return null if no shift found.
return null;
}
Now that the functions are defined, you just need to call the last one to convert specific time, to a shift.
$punchin_time = mktime(15, 55, 0, 4, 15, 2020);
$shift_id = findShift($punchin_time);
Alternatively, don't pass a time in and the current time will be used.
$shift_id = findShift($punchin_time);
mktime
strtotime()
DateTime::getTimestamp()
I'm trying to write a function to calculate the next date that a piece of equipment needs to be checked. I'm using the code below (it's incomplete.)
function get_next_check(){
$today = date(get_option('date_format'));
$first_check = types_get_field_meta_value( 'first_check', $post_id );
// Interval is a number of weeks- ie. month = 4, year = 52
$interval = types_get_field_meta_value( 'interval', $post_id );
// Calculate the next date after today that the check needs to be performed
$next_check = ;
return $next_check;
}
add_shortcode( 'next_check', 'get_next_check' );
I'm guessing I need to create an array of all possible dates, and compare each to today's date, only returning the next one?
Assuming that $first_check is a string with the date in it, and you want the function to return the same, something like this might work:
$week = 60 * 60 * 24 * 7; // number of seconds in a week
$next_check = strtotime($first_check);
while ($next_check < time()) {
$next_check += $week * $interval; // advance the check time by the desired interval
}
return date(get_option('date_format'), $next_check);
You can eliminate your initialization of the $today variable with this.
You can achieve this on the proposed by Greg Schmidt , or alternatively by doing:
// Calculate the next date after today that the check needs to be performed
$next_check = date(get_option('date_format'), strtotime($today." ".$interval." weeks"));
I have a date that goes into a loop that the user specifies. The date will always come from the database formatted as a 'Y-m-d' string. I am aware that I can compare the strings directly as long as they are in that format, however, I have also tried using strtotime to convert the dates to compare them with no luck. I am trying to determine how many paycheck a user has before a payment is due
Here is what I have
$due_date = '2016-12-13';
//count paychecks set to zero and added to by loop
$paychecks = 0;
//users next paycheck ('Y-m-d' ALWAYS)
$next_payday = $user['next_payday']; //equal to '2016-12-02'
//how often they get paid (int)
$frequency = 14;
while(strtotime($next_payday) <= strtotime($due_date)){
//next_payday equals 1480654800 when coming into the loop
//due_date equals 1481605200 when coming into the loop
//add 14 days to the date
$next_payday = date('Y-m-d', strtotime("+" .$frequency." days"));;
//add to paychecks
$paychecks++;
}
The problem is that the loop never stops. It keeps going and going.
Thanks for any help anyone can give me.
Ah, be sure to use strtotime to get integers (representing number of seconds since the epoch) for comparison and multiply your frequency of days by the number of seconds in a day (86400):
$due_date = strtotime('2016-12-25');
//count paychecks set to zero and added to by loop
$paychecks = 0;
//users next paycheck (unixtime for comparison)
$next_payday = strtotime($user['next_payday']);
//how often they get paid (int)
$frequency = 14;
while($next_payday <= $due_date){
//add 14 days to the date
$next_payday += ($frequency * 86400);
//add to paychecks
$paychecks++;
}
This is my first time posting here so I'm sorry if I get something wrong. I'm trying to calculate how many hours overtime a worker has worked based on when they signed in. The problem is that we have different bands of overtime:
If the worker works between 5 and 7 then it's 25% extra per hour
If they worked between 7pm and 10pm then its 50% extran for each hour
If the worker works between 10 and 12 then it's 75% extra
If the worker works between 12am and 7am is 100% more
I need to count how many hours they worked at each of the overtime bands
$number_of_25_percent_hours=0;
$number_of_50_percent_hours=0;
$number_of_75_percent_hours=0;
$number_of_100_percent_hours=0;
$clockInTime=$arr['4'];
$clockOutTime=$arr['5'];
$startingPieces=explode(':',$clockInTime);
$startingHour=$startingPieces[0];
$finishingPieces=explode(':',$clockInTime);
$finishingHour=$finishingPieces[0];
//Regular hours are between 7am and and 5pm
//If the worker works between 5 and 7 then it's 25% extra per hour
if(($startingHour<=5)&&($finishingHour>=6)){$number_of_25_percent_hours++;}
if(($startingHour<=6)&&($finishingHour>=7)){$number_of_25_percent_hours++;}
The problem with using the lines above is that it does not work if for example they worked an hour from 6:30 to 7:30.
I'm interested in finding other ways to do this.
you need to store the data more exactly. From your script it looks as if you were only saving the starting hour - which propably is a full number (1,2,3,4 whatsoever)
You script however needs a exact time representation. There are surely many ways to do this but for the sake of a better Script (and as you will propably be able to use some of these more exact values later on) I'd recommend you to store it as a UNIX Timestamp, then get the hour of the Timestamp :
$startingHour = date('H' $timeStampStored)
and check if it's in any of your "bonus" segments. If the user started working at 6:30, the value will hold 6.
This code is completely off the top of my head, untested etc. It's intended as a suggestion of one method you might use to solve the problem, not as a robust example of working code. It uses integers instead of dates, relies on array data being entered in order etc, and probably wouldn't even run.
The basic idea is to set up the scales for each level of overtime multiplier, as well as the hours for non-overtime pay in an array, then loop through that array checking how many hours of each level of overtime have been worked between the inputted times, meanwhile keeping track of a total billable hours value.
$PayMultipliers = array();
$PayMultipliers[0] = array(17,19,1.25);
$PayMultipliers[1] = array(19,22,1.5);
$PayMultipliers[2] = array(22,24,1.75);
$PayMultipliers[3] = array(0,7,1.5);
$PayMultipliers[4] = array(7, 17, 1);
$Start = 3;
$End = 11;
$TotalHours = 0;
for($i = 0; $i <= count($PayMultipliers); $i++)
{
if($Start > $PayMultipliers[$i][0] && $Start < $PayMultipliers[$i][1])
{
$TotalHours += ($PayMultipliers[$i][1] - $Start) * $PayMultipliers[$i][2];
$Start = $PayMultipliers[$i][1];
}
}
echo $TotalHours;
If you want to calculate from 6:30 to 7:30 you'll have to caclulate in minutes, not hours. You can convert the hours and minutes to timestamps, check each time period, and then convert the seconds back to hours.
<?php
$number_of_overtime_hours = array();
$clockInTime = "18:30:00";
$clockOutTime = "19:30:00";
$startingPieces = explode(':',$clockInTime);
$finishingPieces = explode(':',$clockOutTime);
//Timestamps
$startTimestamp = mktime($startingPieces[0],$startingPieces[1],$startingPieces[2]);
$finishTimestamp = mktime($finishingPieces[0],$finishingPieces[1],$finishingPieces[2]);
//finish after 0h
if ($finishTimestamp < $startTimestamp){
$finishTimestamp += 3600 * 24;
}
//set starting and ending points
$overtimePeriods = array(
25 => array (17,19),
50 => array (19,22),
75 => array (22,24),
100 => array (24,31)
);
$overtimeWork = array();
foreach ($overtimePeriods as $key => $val){
//create Timestamps for overtime periods
$beginTimestamp = mktime($val[0],0,0);
$endTimestamp = mktime($val[1],0,0);
//calculate hours inside the given period
$overtimeWork[$key] = (min($finishTimestamp,$endTimestamp) - max($startTimestamp,$beginTimestamp)) / 3600;
//negative values mean zero work in this period
if ($overtimeWork[$key] < 0) $overtimeWork[$key] = 0;
}
var_dump($overtimeWork);
I had this problem some years ago and back then I implemented a "different logic" in order to deliver the project but the doubt remains in my mind and hopefully with your help I'll be able to understand it now.
Suppose I have some scheduled events on my database that may or may not spawn over several days:
id event start end
-----------------------------------------------
1 fishing trip 2009-12-15 2009-12-15
2 fishCON 2009-12-18 2009-12-20
3 fishXMAS 2009-12-24 2009-12-25
Now I wish to display the events in a calendar, lets take the month of December:
for ($day = 1; $day <= 31; $day++)
{
if (dayHasEvents('2009-12-' . $day) === true)
{
// display the day number w/ a link
}
else
{
// display the day number
}
}
What query should the dayHasEvents() function do to check if there are (or not) events for the day? I'm guessing SELECT .. WHERE .. BETWEEN makes the most sense here but I've no idea how to implement it. Am I in the right direction?
Thanks in advance!
#James:
Lets say we're on December 19th:
SELECT *
FROM events
WHERE start >= '2009-12-19 00:00:00'
AND end <= '2009-12-19 23:59:59'
Should return the event #2, but returns nothing. =\
You should scratch that approach and grab all events for the given month up front so you only need to perform a single query as opposed to N queries where N is the number of days in the month.
You could then store the returned results in a multidimensional array like so:
// assume event results are in an array of objects in $result
$events = array();
foreach ($result as $r) {
// add event month and day as they key index
$key = (int) date('j', strtotime($r->start));
// store entire returned result in array referenced by key
$events[$key][] = $r;
}
Now you'll have a multidimensional array of events for the given month with the key being the day. You can easily check if any events exist on a given day by doing:
$day = 21;
if (!empty($events[$day])) {
// events found, iterate over all events
foreach ($events[$day] as $event) {
// output event result as an example
var_dump($event);
}
}
You're definitely on the right track. Here is how I would go about doing it:
SELECT *
FROM events
WHERE start <= '2009-12-01 00:00:00'
AND end >= '2009-12-01 23:59:59'
And you obviously just replace those date values with the day you're checking on.
James has the right idea on the SQL statement. You definitely don't want to run multiple MySQL SELECTs from within a for loop. If daysHasEvents runs a SELECT that's 31 separate SQL queries. Ouch! What a performance killer.
Instead, load the days of the month that have events into an array (using one SQL query) and then iterate through the days. Something like this:
$sql= "SELECT start, end FROM events WHERE start >= '2009-12-01' AND end <= '2009-12-31'";
$r= mysql_query($sql);
$dates= array();
while ($row = mysql_fetch_assoc($r)) {
// process the entry into a lookup
$start= date('Y-m-d', strtotime($row['start']));
if (!isset($dates[$start])) $dates[$start]= array();
$dates[$start][]= $row;
$end= date('Y-m-d', strtotime($row['end']));
if ($end != $start) {
if (!isset($dates[$end])) $dates[$end]= array();
$dates[$end][]= $row;
}
}
// Then step through the days of the month and check for entries for each day:
for ($day = 1; $day <= 31; $day++)
{
$d= sprintf('2009-12-%02d', $day);
if (isset($dates[$d])) {
// display the day number w/ a link
} else {
// display the day number
}
}
For your purposes a better SQL statement would be one that grabs the start date and the number of events on each day. This statement will only work properly if the start column is date column with no time component:
$sql= "SELECT start, end, COUNT(*) events_count FROM events WHERE start >= '2009-12-01' AND end <= '2009-12-31' GROUP BY start, end";