title: How to specify explicitly the month section while plotting a seasonal plot?
body: <p>I am trying to learn forecast using fpp2 package on bitcoin data. The bitcoin_ts excel just has two columns, one the date column another the closing price for each date.</p>
  
  <pre><code>library(fpp2)
  bitcoin_ts &lt;- read_excel("bitcoin_ts.xlsx")
  head(bitcoin_ts)
  
  myts &lt;- ts(bitcoin_ts[,2], start = c(2013, 2), frequency = 366)
  ##autoplot(myts, facets = FALSE)
  ggseasonplot(myts)
  </code></pre>
  
  <p>As beginning of the data is 2013 and from the month of April, which is the second quarter, I specified start as 2013 and 2 and frequency I gave as number of days in a year.</p>
  
  <p>I get a graph as attached the lower scale (season), my requirement is to show months but I guess due to the all the dates being included in the data it is getting superimposed. How can I fix this to achieve only months over there?</p>
  
  <p><a href="https://i.stack.imgur.com/s44BL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/s44BL.png" alt="bitcoins"></a></p>
  
  <p>I would like to see something similar to this chart (of course the data upon which this chart was plotted had only year and month (ex: Mar-81)</p>
  
  <p><a href="https://i.stack.imgur.com/W7rnG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/W7rnG.png" alt="desired chart"></a></p>
  
  <p>Unable to attach the entire 1655 observations as the this textbox is set to a limit of 30K characters.</p>
  
  <p>However I attaching the link to the dataset as well.</p>
  
  <p><a href="https://www.dropbox.com/s/20abkbsu3ktuuwk/bitcoin_ts.xlsx?dl=0" rel="nofollow noreferrer">Complete Dataset</a></p>
  
  <p>Below find the sample of first 500,</p>
  
  <pre><code>&gt; dput(head(bitcoin_ts,500))
  structure(list(Date = structure(c(1367107200, 1367193600, 1367280000, 
  1367366400, 1367452800, 1367539200, 1367625600, 1367712000, 1367798400, 
  1367884800, 1367971200, 1368057600, 1368144000, 1368230400, 1368316800, 
  1368403200, 1368489600, 1368576000, 1368662400, 1368748800, 1368835200, 
  1368921600, 1369008000, 1369094400, 1369180800, 1369267200, 1369353600, 
  1369440000, 1369526400, 1369612800, 1369699200, 1369785600, 1369872000, 
  1369958400, 1370044800, 1370131200, 1370217600, 1370304000, 1370390400, 
  1370476800, 1370563200, 1370649600, 1370736000, 1370822400, 1370908800, 
  1370995200, 1371081600, 1371168000, 1371254400, 1371340800, 1371427200, 
  1371513600, 1371600000, 1371686400, 1371772800, 1371859200, 1371945600, 
  1372032000, 1372118400, 1372204800, 1372291200, 1372377600, 1372464000, 
  1372550400, 1372636800, 1372723200, 1372809600, 1372896000, 1372982400, 
  1373068800, 1373155200, 1373241600, 1373328000, 1373414400, 1373500800, 
  1373587200, 1373673600, 1373760000, 1373846400, 1373932800, 1374019200, 
  1374105600, 1374192000, 1374278400, 1374364800, 1374451200, 1374537600, 
  1374624000, 1374710400, 1374796800, 1374883200, 1374969600, 1375056000, 
  1375142400, 1375228800, 1375315200, 1375401600, 1375488000, 1375574400, 
  1375660800, 1375747200, 1375833600, 1375920000, 1376006400, 1376092800, 
  1376179200, 1376265600, 1376352000, 1376438400, 1376524800, 1376611200, 
  1376697600, 1376784000, 1376870400, 1376956800, 1377043200, 1377129600, 
  1377216000, 1377302400, 1377388800, 1377475200, 1377561600, 1377648000, 
  1377734400, 1377820800, 1377907200, 1377993600, 1378080000, 1378166400, 
  1378252800, 1378339200, 1378425600, 1378512000, 1378598400, 1378684800, 
  1378771200, 1378857600, 1378944000, 1379030400, 1379116800, 1379203200, 
  1379289600, 1379376000, 1379462400, 1379548800, 1379635200, 1379721600, 
  1379808000, 1379894400, 1379980800, 1380067200, 1380153600, 1380240000, 
  1380326400, 1380412800, 1380499200, 1380585600, 1380672000, 1380758400, 
  1380844800, 1380931200, 1381017600, 1381104000, 1381190400, 1381276800, 
  1381363200, 1381449600, 1381536000, 1381622400, 1381708800, 1381795200, 
  1381881600, 1381968000, 1382054400, 1382140800, 1382227200, 1382313600, 
  1382400000, 1382486400, 1382572800, 1382659200, 1382745600, 1382832000, 
  1382918400, 1383004800, 1383091200, 1383177600, 1383264000, 1383350400, 
  1383436800, 1383523200, 1383609600, 1383696000, 1383782400, 1383868800, 
  1383955200, 1384041600, 1384128000, 1384214400, 1384300800, 1384387200, 
  1384473600, 1384560000, 1384646400, 1384732800, 1384819200, 1384905600, 
  1384992000, 1385078400, 1385164800, 1385251200, 1385337600, 1385424000, 
  1385510400, 1385596800, 1385683200, 1385769600, 1385856000, 1385942400, 
  1386028800, 1386115200, 1386201600, 1386288000, 1386374400, 1386460800, 
  1386547200, 1386633600, 1386720000, 1386806400, 1386892800, 1386979200, 
  1387065600, 1387152000, 1387238400, 1387324800, 1387411200, 1387497600, 
  1387584000, 1387670400, 1387756800, 1387843200, 1387929600, 1388016000, 
  1388102400, 1388188800, 1388275200, 1388361600, 1388448000, 1388534400, 
  1388620800, 1388707200, 1388793600, 1388880000, 1388966400, 1389052800, 
  1389139200, 1389225600, 1389312000, 1389398400, 1389484800, 1389571200, 
  1389657600, 1389744000, 1389830400, 1389916800, 1390003200, 1390089600, 
  1390176000, 1390262400, 1390348800, 1390435200, 1390521600, 1390608000, 
  1390694400, 1390780800, 1390867200, 1390953600, 1391040000, 1391126400, 
  1391212800, 1391299200, 1391385600, 1391472000, 1391558400, 1391644800, 
  1391731200, 1391817600, 1391904000, 1391990400, 1392076800, 1392163200, 
  1392249600, 1392336000, 1392422400, 1392508800, 1392595200, 1392681600, 
  1392768000, 1392854400, 1392940800, 1393027200, 1393113600, 1393200000, 
  1393286400, 1393372800, 1393459200, 1393545600, 1393632000, 1393718400, 
  1393804800, 1393891200, 1393977600, 1394064000, 1394150400, 1394236800, 
  1394323200, 1394409600, 1394496000, 1394582400, 1394668800, 1394755200, 
  1394841600, 1394928000, 1395014400, 1395100800, 1395187200, 1395273600, 
  1395360000, 1395446400, 1395532800, 1395619200, 1395705600, 1395792000, 
  1395878400, 1395964800, 1396051200, 1396137600, 1396224000, 1396310400, 
  1396396800, 1396483200, 1396569600, 1396656000, 1396742400, 1396828800, 
  1396915200, 1397001600, 1397088000, 1397174400, 1397260800, 1397347200, 
  1397433600, 1397520000, 1397606400, 1397692800, 1397779200, 1397865600, 
  1397952000, 1398038400, 1398124800, 1398211200, 1398297600, 1398384000, 
  1398470400, 1398556800, 1398643200, 1398729600, 1398816000, 1398902400, 
  1398988800, 1399075200, 1399161600, 1399248000, 1399334400, 1399420800, 
  1399507200, 1399593600, 1399680000, 1399766400, 1399852800, 1399939200, 
  1400025600, 1400112000, 1400198400, 1400284800, 1400371200, 1400457600, 
  1400544000, 1400630400, 1400716800, 1400803200, 1400889600, 1400976000, 
  1401062400, 1401148800, 1401235200, 1401321600, 1401408000, 1401494400, 
  1401580800, 1401667200, 1401753600, 1401840000, 1401926400, 1402012800, 
  1402099200, 1402185600, 1402272000, 1402358400, 1402444800, 1402531200, 
  1402617600, 1402704000, 1402790400, 1402876800, 1402963200, 1403049600, 
  1403136000, 1403222400, 1403308800, 1403395200, 1403481600, 1403568000, 
  1403654400, 1403740800, 1403827200, 1403913600, 1.404e+09, 1404086400, 
  1404172800, 1404259200, 1404345600, 1404432000, 1404518400, 1404604800, 
  1404691200, 1404777600, 1404864000, 1404950400, 1405036800, 1405123200, 
  1405209600, 1405296000, 1405382400, 1405468800, 1405555200, 1405641600, 
  1405728000, 1405814400, 1405900800, 1405987200, 1406073600, 1406160000, 
  1406246400, 1406332800, 1406419200, 1406505600, 1406592000, 1406678400, 
  1406764800, 1406851200, 1406937600, 1407024000, 1407110400, 1407196800, 
  1407283200, 1407369600, 1407456000, 1407542400, 1407628800, 1407715200, 
  1407801600, 1407888000, 1407974400, 1408060800, 1408147200, 1408233600, 
  1408320000, 1408406400, 1408492800, 1408579200, 1408665600, 1408752000, 
  1408838400, 1408924800, 1409011200, 1409097600, 1409184000, 1409270400, 
  1409356800, 1409443200, 1409529600, 1409616000, 1409702400, 1409788800, 
  1409875200, 1409961600, 1410048000, 1410134400, 1410220800), class = c("POSIXct", 
  "POSIXt"), tzone = "UTC"), Close = c(134.21, 144.54, 139, 116.99, 
  105.21, 97.75, 112.5, 115.91, 112.3, 111.5, 113.57, 112.67, 117.2, 
  115.24, 115, 117.98, 111.5, 114.22, 118.76, 123.02, 123.5, 121.99, 
  122, 122.88, 123.89, 126.7, 133.2, 131.98, 133.48, 129.75, 129, 
  132.3, 128.8, 129, 129.3, 122.29, 122.22, 121.42, 121.65, 118, 
  111.5, 108.3, 100, 106.35, 108.9, 108.15, 104, 99.98, 99.99, 
  99.51, 101.7, 107.4, 108.25, 110.15, 109.5, 108.3, 107.6, 102.74, 
  103.95, 104, 101.44, 94.65, 94.99, 96.61, 88.05, 90.13, 77.53, 
  80.53, 68.43, 70.28, 74.56, 76.52, 76.69, 86.76, 88.98, 93.59, 
  98.13, 94.69, 98.4, 97.45, 98.5, 90.58, 92.17, 89.39, 90.76, 
  91.61, 95.56, 94.51, 96.9, 96.02, 94.12, 99.76, 101.2, 107.99, 
  106.09, 104, 104.5, 104, 105.14, 106.22, 106.75, 106.75, 103, 
  102.8, 103, 105, 106.64, 109, 112.56, 109.99, 108.99, 113.5, 
  113.5, 119, 121.2, 123.3, 121.15, 118.5, 120.05, 122.11, 120.06, 
  126.5, 122.62, 122.39, 133.49, 135.35, 138.34, 135.85, 136.77, 
  126.74, 126.43, 119.15, 124.15, 121.66, 127.11, 125.91, 135.25, 
  133.13, 134.98, 129.22, 130.37, 131.72, 131.66, 131.47, 129.65, 
  127.04, 127.43, 129.12, 125.95, 127.25, 128.22, 128.38, 133.78, 
  134.78, 137.34, 133, 132.18, 114.13, 123.63, 129.01, 128.55, 
  129, 126.94, 126, 130.69, 130.59, 130.9, 135.19, 138.13, 140.52, 
  145.24, 142.55, 146.25, 155.96, 172.42, 174.61, 182.21, 193.76, 
  213.62, 198.23, 186.69, 177.32, 196.44, 198.55, 204.39, 199.97, 
  204, 206.18, 206.22, 215.05, 229.1, 245.24, 262.5, 296.41, 338.11, 
  339.11, 326.62, 342.44, 360.33, 407.37, 420.2, 417.95, 440.22, 
  492.11, 703.56, 584.61, 590.83, 722.43, 771.44, 797.82, 774.25, 
  799.11, 928.1, 1001.96, 1031.95, 1131.97, 1129.43, 955.85, 1043.33, 
  1078.28, 1151.17, 1045.11, 829.45, 698.23, 795.87, 893.19, 988.51, 
  878.48, 873.26, 892.58, 872.6, 876.12, 705.97, 682.12, 522.7, 
  691.96, 625.32, 605.66, 617.18, 673.41, 665.58, 682.21, 761.98, 
  735.07, 727.83, 745.05, 756.13, 754.01, 771.4, 802.39, 818.72, 
  859.51, 933.53, 953.29, 802, 842.72, 846.86, 868.48, 913.95, 
  863.22, 841.2, 833.27, 860.9, 835.63, 814.64, 840, 870.96, 870.2, 
  863.91, 845.59, 822.04, 797.07, 853.61, 885.28, 771.39, 812.51, 
  826, 819.03, 829.92, 832.58, 825.37, 823.83, 827.96, 811.91, 
  781.55, 712.4, 673.92, 682.9, 681.03, 672.17, 651.72, 605.24, 
  661.99, 650.92, 616.63, 626.27, 626.6, 623.03, 556.14, 574.16, 
  605.42, 605.82, 546.32, 538.71, 582.69, 578.77, 549.26, 565.61, 
  559.79, 667.76, 666.78, 665.51, 663.86, 629.15, 617.45, 636.96, 
  627.79, 634.11, 632.1, 638.14, 628.8, 636.12, 631.11, 622.37, 
  614.83, 609.89, 588.77, 571.49, 565.04, 561.27, 583.41, 583.92, 
  580.83, 471.24, 495.67, 491.17, 460.27, 457, 478.38, 437.14, 
  444.72, 447.53, 461.91, 460.5, 449.42, 453.09, 442.73, 365.18, 
  420.95, 421.12, 414.06, 458.79, 515.59, 527.39, 495.96, 479.64, 
  501.56, 498.17, 495.77, 487.92, 491.3, 500.46, 461.45, 458.6, 
  436.39, 440.29, 447.21, 447.64, 457.76, 449.38, 437.76, 436.4, 
  433.48, 428.96, 438.82, 440.17, 449.46, 454.43, 438.89, 441.46, 
  440.67, 443.97, 447.25, 448.06, 448.9, 446.26, 446.18, 485.72, 
  491.77, 524.58, 520.22, 525.14, 571.59, 583.42, 571.24, 577.06, 
  568.18, 615.33, 623.68, 630.23, 660.62, 667.61, 641.61, 659.26, 
  653.7, 654.97, 656.14, 649.16, 653.15, 633.02, 586.95, 600.16, 
  577.36, 592.94, 592.19, 610.86, 607.96, 598.07, 594.15, 594.99, 
  602.27, 593.98, 582.36, 566.34, 581.14, 597.26, 596.55, 602.72, 
  639.8, 640.81, 650.88, 645.16, 630.69, 631.46, 635.81, 624.09, 
  624.82, 624.51, 616.76, 632, 633.71, 626.5, 619.32, 621.59, 616.8, 
  623.09, 628.78, 628.51, 623.9, 622.21, 621.55, 619.41, 601.73, 
  601.09, 595.81, 593.85, 585.69, 584.73, 567.29, 586.24, 594.92, 
  589.33, 586.67, 588.78, 585.44, 584.65, 588.87, 592.58, 589.37, 
  591.06, 576.37, 569.64, 546.66, 505.97, 497.01, 519.71, 491.8, 
  461.46, 485.25, 511.98, 517.24, 514.04, 498.07, 508.29, 502.5, 
  511.57, 511.15, 507.81, 508.52, 504.25, 477.76, 474.88, 477.43, 
  477.59, 489.66, 483.34, 484.83, 482.28, 474.6, 475.26)), .Names = c("Date", 
  "Close"), row.names = c(NA, -500L), class = c("tbl_df", "tbl", 
  "data.frame"))
  </code></pre>