Bug typo in timezonetime.coffee

[jacobg]

toISOString: -> @walltime.toISOString()

It should read 'wallTime' (camel case), not 'walltime'

[jgable]

Good find. Published to npm as version 0.0.8 and available in the new client files.

Noticed you also found the timezone-js lacking in correctness, have any problems with our library yet?

[jacobg]

Thanks Jacob.

I'm just starting to try out walltime, so I plan to follow up with more feedback. I am likely to drop timezone-js due to it DST issues. Its code is so disorganized that I don't even want to try to fix it. Walltime looks much cleaner, and I've heard good feedback on the web. The only issue I am having with walltime is figuring out how to use the API properly, but I think as I play around with it, I'll figure it out on my own. One of the main reasons I chose timezone-js originally is because it emulates the native Date object, which made it easy to integrate with Ext JS. I'm hoping integrating walltime with Ext JS won't be too difficult either.

[jgable]

Cool. Thanks for the feedback.

The two main entry points for the API right now are UTCToWallTime and WallTimeToUTC.

Here are some helper functions we use on sproutsocial:

// ** These are attached to a Ss.timezone object.

// A wrapper around WallTime that allows specifying a time zone.
localDate: function localDate(timestamp, region) {
    // Default to user php zone
    region || (region = Ss.user.time_zone_daylight_savings);

    return WallTime.UTCToWallTime(timestamp, region);
},
utcDate: function utcDate(region, year, month, day, hour, minute, second, millisecond) {
    region = region || Ss.user.time_zone_daylight_savings;
    year = year || new Date().getFullYear();

    return WallTime.WallTimeToUTC(region, year, month, day, hour, minute, second, millisecond);
},

// Get a specific time of day for a time zone, based on the day you pass in.
localDateTimeOfDay: function localDateTimeOfDay(timestamp, region, hour, minute, seconds) {
    // Default to user php zone
    region || (region = Ss.user.time_zone_daylight_savings);
    // Default everything to 0.
    hour || (hour = 0);
    minute || (minute = 0);
    seconds || (seconds = 0);

    // Get walltime of passed in timestamp
    var localToday = Ss.timezone.localDate(timestamp, region),
        // Get morning of todays walltime in UTC 
        utcTimeOfDay = Ss.timezone.utcDate(region, localToday.getFullYear(), localToday.getMonth(), localToday.getDate(), hour, minute, seconds, 0);

    // Return the localDate equivalent of the utc representation of midnight.
    return Ss.timezone.localDate(utcTimeOfDay.getTime(), region);
},

// Get the morning of a specific day
localDateMorning: function localDateMorning(timestamp, region) {
    return Ss.timezone.localDateTimeOfDay(timestamp, region, 0);
},

// Add hours, minutes or days to a day and get back the timezone specific date information
localDatePlus: function localDatePlus(timestamp, region, plusYears, plusMonths, plusDays, plusHours, plusMinutes, plusSeconds, plusMilliseconds) {
    // Default to user php zone
    region || (region = Ss.user.time_zone_daylight_savings);
    // Default everything to 0
    plusYears || (plusYears = 0);
    plusMonths || (plusMonths = 0);
    plusDays || (plusDays = 0);
    plusHours || (plusHours = 0);
    plusMinutes || (plusMinutes = 0);
    plusSeconds || (plusSeconds = 0);
    plusMilliseconds || (plusMilliseconds = 0);

    // Get walltime of passed in timestamp
    var localDate = Ss.timezone.localDate(timestamp, region),
        // Get utc version with the time added.
        utcWithAdded = Ss.timezone.utcDate(region, localDate.getFullYear() + plusYears, localDate.getMonth() + plusMonths, localDate.getDate() + plusDays, localDate.getHours() + plusHours, localDate.getMinutes() + plusMinutes, localDate.getSeconds() + plusSeconds, localDate.getMilliseconds() + plusMilliseconds);

    return Ss.timezone.localDate(utcWithAdded.getTime(), region);
}

From there you can kind of extrapolate things out to do things like date ranges in a safe timezone agnostic way.

// returns the beginning of the user's day in milliseconds
beginningOfToday : function(){
    return Ss.timezone.localDateMorning(new Date().getTime()).utc.getTime();
},
beginningOfYesterday : function(){
    var today = Ss.timezone.localDate(new Date().getTime()),
        yesterdayMorningUtc = Ss.timezone.utcDate(Ss.user.time_zone_daylight_savings, today.getFullYear(), today.getMonth(), today.getDate() - 1, 0);

    return yesterdayMorningUtc.getTime();
},
endOfYesterday : function(){
    var today = Ss.timezone.localDate(new Date().getTime()),
        yesterdayMidnightUtc = Ss.timezone.utcDate(Ss.user.time_zone_daylight_savings, today.getFullYear(), today.getMonth(), today.getDate() - 1, 23, 59, 59);

    return yesterdayMidnightUtc.getTime();
},
beginningOfThisWeek : function(){
    var beginningOfToday = Ss.timezone.localDateMorning(new Date().getTime()),
        beginDate = beginningOfToday.getDate() - beginningOfToday.getDay();

    return Ss.timezone.utcDate(Ss.user.time_zone_daylight_savings, beginningOfToday.getFullYear(), beginningOfToday.getMonth(), beginDate);
},
beginningOfLastWeek : function(){
    var beginningOfToday = Ss.timezone.localDateMorning(new Date().getTime()),
        // Beginning of the week, -7 to go back one more week.
        beginDate = (beginningOfToday.getDate() - beginningOfToday.getDay()) - 7;

    return Ss.timezone.utcDate(Ss.user.time_zone_daylight_savings, beginningOfToday.getFullYear(), beginningOfToday.getMonth(), beginDate);
},
endOfLastWeek : function(){
    // Beginning of this week minus 1 day, then specify 11:59 PM
    var beginningOfToday = Ss.timezone.localDateMorning(new Date().getTime()),
        beginDate = (beginningOfToday.getDate() - beginningOfToday.getDay()) - 1;

    return Ss.timezone.utcDate(Ss.user.time_zone_daylight_savings, beginningOfToday.getFullYear(), beginningOfToday.getMonth(), beginDate, 23, 59, 59);
},
beginningOfThisMonth : function(){
    var today = Ss.timezone.localDate(new Date().getTime());

    return Ss.timezone.utcDate(Ss.user.time_zone_daylight_savings, today.getFullYear(), today.getMonth(), 1);
},
beginningOfLastMonth : function(){
    // Today, minus one month and set the date to 1.
    var today = Ss.timezone.localDate(new Date().getTime());

    return Ss.timezone.utcDate(Ss.user.time_zone_daylight_savings, today.getFullYear(), today.getMonth() - 1, 1);
},
endOfLastMonth : function(){
    // This is tricky; beginning of the current month, minus one day, 11:59 PM
    var beginOfMonth = Ss.timezone.localDate(this.beginningOfThisMonth().getTime());

    return Ss.timezone.utcDate(Ss.user.time_zone_daylight_savings, beginOfMonth.getFullYear(), beginOfMonth.getMonth(), beginOfMonth.getDate() - 1, 23, 59, 59);
}

Hope that helps.

[jacobg]

Thanks a lot. A few thoughts on additions that would be valuable for me: (1) more date formatting options (example here: http://docs.sencha.com/ext-js/4-2/?print=/api/Ext.Date) (2) given a TimeZoneTime, get a native Date object whose local date-time equals the wall time) (3) allow WallTimeToUTC to accept a native Date object whose local date-time equals the wall time (inverse of # 2)

If 2-3 need more elaboration, please let me know.

[jacobg]

FYI, your localDatePlus() method has unexpected results (unexpected for me at least) when you add a month to Jan 31, or a year to Feb 29. It will overflow to the next month in that case (e.g., March 3 instead of Feb 28).

[jgable]

Interesting. Well, that actually imitates what Javascript would do as well.

var d = new Date(2013, 0, 31, 8);
// Thu Jan 31 2013 08:00:00 GMT-0600 (CST)
d.setMonth(1);
// Sun Mar 03 2013 08:00:00 GMT-0600 (CST)

Dates are hard :/

For the time being we're happy to just emulate native date oddities.

[jacobg]

True. I'm comparing to Ext JS, which has an Ext.Date.add function that handles overflow (see http://docs.sencha.com/ext-js/4-2/source/Date2.html#Ext-Date-method-add). It's very useful, for example, if an application needs to calculate monthly or yearly periods based on a starting date.